diff --git a/src/doc/unstable-book/src/language-features/optin-builtin-traits.md b/src/doc/unstable-book/src/language-features/optin-builtin-traits.md
index 5c8124c9c6b7d..1ec8b8bf8ddbd 100644
--- a/src/doc/unstable-book/src/language-features/optin-builtin-traits.md
+++ b/src/doc/unstable-book/src/language-features/optin-builtin-traits.md
@@ -16,7 +16,7 @@ has explicitly opted out via a negative impl.
 [`Sync`]: https://doc.rust-lang.org/std/marker/trait.Sync.html
 
 ```rust,ignore
-impl !Type for Trait
+impl !Trait for Type
 ```
 
 Example:
diff --git a/src/librustc/ty/util.rs b/src/librustc/ty/util.rs
index 1f512f1dde7d6..8ace84b7832e6 100644
--- a/src/librustc/ty/util.rs
+++ b/src/librustc/ty/util.rs
@@ -1047,10 +1047,7 @@ pub fn needs_drop_components(
         // Foreign types can never have destructors.
         ty::Foreign(..) => Ok(SmallVec::new()),
 
-        // Pessimistically assume that all generators will require destructors
-        // as we don't know if a destructor is a noop or not until after the MIR
-        // state transformation pass.
-        ty::Generator(..) | ty::Dynamic(..) | ty::Error => Err(AlwaysRequiresDrop),
+        ty::Dynamic(..) | ty::Error => Err(AlwaysRequiresDrop),
 
         ty::Slice(ty) => needs_drop_components(ty, target_layout),
         ty::Array(elem_ty, size) => {
@@ -1083,7 +1080,8 @@ pub fn needs_drop_components(
         | ty::Placeholder(..)
         | ty::Opaque(..)
         | ty::Infer(_)
-        | ty::Closure(..) => Ok(smallvec![ty]),
+        | ty::Closure(..)
+        | ty::Generator(..) => Ok(smallvec![ty]),
     }
 }
 
diff --git a/src/librustc_codegen_llvm/back/write.rs b/src/librustc_codegen_llvm/back/write.rs
index 2327b96e26c36..5759eb2991a81 100644
--- a/src/librustc_codegen_llvm/back/write.rs
+++ b/src/librustc_codegen_llvm/back/write.rs
@@ -16,7 +16,7 @@ use crate::ModuleLlvm;
 use log::debug;
 use rustc::bug;
 use rustc::ty::TyCtxt;
-use rustc_codegen_ssa::back::write::{run_assembler, CodegenContext, ModuleConfig};
+use rustc_codegen_ssa::back::write::{run_assembler, CodegenContext, EmbedBitcode, ModuleConfig};
 use rustc_codegen_ssa::traits::*;
 use rustc_codegen_ssa::{CompiledModule, ModuleCodegen, RLIB_BYTECODE_EXTENSION};
 use rustc_data_structures::small_c_str::SmallCStr;
@@ -634,30 +634,24 @@ pub(crate) unsafe fn codegen(
             f(cpm)
         }
 
-        // If we don't have the integrated assembler, then we need to emit asm
-        // from LLVM and use `gcc` to create the object file.
-        let asm_to_obj = config.emit_obj && config.no_integrated_as;
-
-        // Change what we write and cleanup based on whether obj files are
-        // just llvm bitcode. In that case write bitcode, and possibly
-        // delete the bitcode if it wasn't requested. Don't generate the
-        // machine code, instead copy the .o file from the .bc
-        let write_bc = config.emit_bc || config.obj_is_bitcode;
-        let rm_bc = !config.emit_bc && config.obj_is_bitcode;
-        let write_obj = config.emit_obj && !config.obj_is_bitcode && !asm_to_obj;
-        let copy_bc_to_obj = config.emit_obj && config.obj_is_bitcode;
+        // Two things to note:
+        // - If object files are just LLVM bitcode we write bitcode, copy it to
+        //   the .o file, and delete the bitcode if it wasn't otherwise
+        //   requested.
+        // - If we don't have the integrated assembler then we need to emit
+        //   asm from LLVM and use `gcc` to create the object file.
 
         let bc_out = cgcx.output_filenames.temp_path(OutputType::Bitcode, module_name);
         let obj_out = cgcx.output_filenames.temp_path(OutputType::Object, module_name);
 
-        if write_bc || config.emit_bc_compressed || config.embed_bitcode {
+        if config.bitcode_needed() {
             let _timer = cgcx
                 .prof
                 .generic_activity_with_arg("LLVM_module_codegen_make_bitcode", &module.name[..]);
             let thin = ThinBuffer::new(llmod);
             let data = thin.data();
 
-            if write_bc {
+            if config.emit_bc || config.obj_is_bitcode {
                 let _timer = cgcx.prof.generic_activity_with_arg(
                     "LLVM_module_codegen_emit_bitcode",
                     &module.name[..],
@@ -668,7 +662,7 @@ pub(crate) unsafe fn codegen(
                 }
             }
 
-            if config.embed_bitcode {
+            if config.embed_bitcode == EmbedBitcode::Full {
                 let _timer = cgcx.prof.generic_activity_with_arg(
                     "LLVM_module_codegen_embed_bitcode",
                     &module.name[..],
@@ -688,81 +682,75 @@ pub(crate) unsafe fn codegen(
                     diag_handler.err(&msg);
                 }
             }
-        } else if config.embed_bitcode_marker {
+        } else if config.embed_bitcode == EmbedBitcode::Marker {
             embed_bitcode(cgcx, llcx, llmod, None);
         }
 
-        {
-            if config.emit_ir {
-                let _timer = cgcx
-                    .prof
-                    .generic_activity_with_arg("LLVM_module_codegen_emit_ir", &module.name[..]);
-                let out = cgcx.output_filenames.temp_path(OutputType::LlvmAssembly, module_name);
-                let out_c = path_to_c_string(&out);
-
-                extern "C" fn demangle_callback(
-                    input_ptr: *const c_char,
-                    input_len: size_t,
-                    output_ptr: *mut c_char,
-                    output_len: size_t,
-                ) -> size_t {
-                    let input = unsafe {
-                        slice::from_raw_parts(input_ptr as *const u8, input_len as usize)
-                    };
-
-                    let input = match str::from_utf8(input) {
-                        Ok(s) => s,
-                        Err(_) => return 0,
-                    };
-
-                    let output = unsafe {
-                        slice::from_raw_parts_mut(output_ptr as *mut u8, output_len as usize)
-                    };
-                    let mut cursor = io::Cursor::new(output);
-
-                    let demangled = match rustc_demangle::try_demangle(input) {
-                        Ok(d) => d,
-                        Err(_) => return 0,
-                    };
-
-                    if write!(cursor, "{:#}", demangled).is_err() {
-                        // Possible only if provided buffer is not big enough
-                        return 0;
-                    }
-
-                    cursor.position() as size_t
+        if config.emit_ir {
+            let _timer = cgcx
+                .prof
+                .generic_activity_with_arg("LLVM_module_codegen_emit_ir", &module.name[..]);
+            let out = cgcx.output_filenames.temp_path(OutputType::LlvmAssembly, module_name);
+            let out_c = path_to_c_string(&out);
+
+            extern "C" fn demangle_callback(
+                input_ptr: *const c_char,
+                input_len: size_t,
+                output_ptr: *mut c_char,
+                output_len: size_t,
+            ) -> size_t {
+                let input =
+                    unsafe { slice::from_raw_parts(input_ptr as *const u8, input_len as usize) };
+
+                let input = match str::from_utf8(input) {
+                    Ok(s) => s,
+                    Err(_) => return 0,
+                };
+
+                let output = unsafe {
+                    slice::from_raw_parts_mut(output_ptr as *mut u8, output_len as usize)
+                };
+                let mut cursor = io::Cursor::new(output);
+
+                let demangled = match rustc_demangle::try_demangle(input) {
+                    Ok(d) => d,
+                    Err(_) => return 0,
+                };
+
+                if write!(cursor, "{:#}", demangled).is_err() {
+                    // Possible only if provided buffer is not big enough
+                    return 0;
                 }
 
-                let result = llvm::LLVMRustPrintModule(llmod, out_c.as_ptr(), demangle_callback);
-                result.into_result().map_err(|()| {
-                    let msg = format!("failed to write LLVM IR to {}", out.display());
-                    llvm_err(diag_handler, &msg)
-                })?;
+                cursor.position() as size_t
             }
 
-            if config.emit_asm || asm_to_obj {
-                let _timer = cgcx
-                    .prof
-                    .generic_activity_with_arg("LLVM_module_codegen_emit_asm", &module.name[..]);
-                let path = cgcx.output_filenames.temp_path(OutputType::Assembly, module_name);
+            let result = llvm::LLVMRustPrintModule(llmod, out_c.as_ptr(), demangle_callback);
+            result.into_result().map_err(|()| {
+                let msg = format!("failed to write LLVM IR to {}", out.display());
+                llvm_err(diag_handler, &msg)
+            })?;
+        }
 
-                // We can't use the same module for asm and binary output, because that triggers
-                // various errors like invalid IR or broken binaries, so we might have to clone the
-                // module to produce the asm output
-                let llmod = if config.emit_obj { llvm::LLVMCloneModule(llmod) } else { llmod };
-                with_codegen(tm, llmod, config.no_builtins, |cpm| {
-                    write_output_file(
-                        diag_handler,
-                        tm,
-                        cpm,
-                        llmod,
-                        &path,
-                        llvm::FileType::AssemblyFile,
-                    )
-                })?;
-            }
+        let config_emit_normal_obj = config.emit_obj && !config.obj_is_bitcode;
 
-            if write_obj {
+        if config.emit_asm || (config_emit_normal_obj && config.no_integrated_as) {
+            let _timer = cgcx
+                .prof
+                .generic_activity_with_arg("LLVM_module_codegen_emit_asm", &module.name[..]);
+            let path = cgcx.output_filenames.temp_path(OutputType::Assembly, module_name);
+
+            // We can't use the same module for asm and binary output, because that triggers
+            // various errors like invalid IR or broken binaries, so we might have to clone the
+            // module to produce the asm output
+            let llmod = if config.emit_obj { llvm::LLVMCloneModule(llmod) } else { llmod };
+            with_codegen(tm, llmod, config.no_builtins, |cpm| {
+                write_output_file(diag_handler, tm, cpm, llmod, &path, llvm::FileType::AssemblyFile)
+            })?;
+        }
+
+        if config_emit_normal_obj {
+            if !config.no_integrated_as {
                 let _timer = cgcx
                     .prof
                     .generic_activity_with_arg("LLVM_module_codegen_emit_obj", &module.name[..]);
@@ -776,7 +764,7 @@ pub(crate) unsafe fn codegen(
                         llvm::FileType::ObjectFile,
                     )
                 })?;
-            } else if asm_to_obj {
+            } else {
                 let _timer = cgcx
                     .prof
                     .generic_activity_with_arg("LLVM_module_codegen_asm_to_obj", &module.name[..]);
@@ -789,17 +777,19 @@ pub(crate) unsafe fn codegen(
             }
         }
 
-        if copy_bc_to_obj {
-            debug!("copying bitcode {:?} to obj {:?}", bc_out, obj_out);
-            if let Err(e) = link_or_copy(&bc_out, &obj_out) {
-                diag_handler.err(&format!("failed to copy bitcode to object file: {}", e));
+        if config.obj_is_bitcode {
+            if config.emit_obj {
+                debug!("copying bitcode {:?} to obj {:?}", bc_out, obj_out);
+                if let Err(e) = link_or_copy(&bc_out, &obj_out) {
+                    diag_handler.err(&format!("failed to copy bitcode to object file: {}", e));
+                }
             }
-        }
 
-        if rm_bc {
-            debug!("removing_bitcode {:?}", bc_out);
-            if let Err(e) = fs::remove_file(&bc_out) {
-                diag_handler.err(&format!("failed to remove bitcode: {}", e));
+            if !config.emit_bc {
+                debug!("removing_bitcode {:?}", bc_out);
+                if let Err(e) = fs::remove_file(&bc_out) {
+                    diag_handler.err(&format!("failed to remove bitcode: {}", e));
+                }
             }
         }
 
diff --git a/src/librustc_codegen_ssa/back/write.rs b/src/librustc_codegen_ssa/back/write.rs
index 746ab34d2844d..a4b5acdcd18a2 100644
--- a/src/librustc_codegen_ssa/back/write.rs
+++ b/src/librustc_codegen_ssa/back/write.rs
@@ -51,6 +51,14 @@ use std::thread;
 
 const PRE_LTO_BC_EXT: &str = "pre-lto.bc";
 
+/// The kind of bitcode to embed in object files.
+#[derive(PartialEq)]
+pub enum EmbedBitcode {
+    None,
+    Marker,
+    Full,
+}
+
 /// Module-specific configuration for `optimize_and_codegen`.
 pub struct ModuleConfig {
     /// Names of additional optimization passes to run.
@@ -74,7 +82,6 @@ pub struct ModuleConfig {
     pub emit_no_opt_bc: bool,
     pub emit_bc: bool,
     pub emit_bc_compressed: bool,
-    pub emit_lto_bc: bool,
     pub emit_ir: bool,
     pub emit_asm: bool,
     pub emit_obj: bool,
@@ -94,8 +101,7 @@ pub struct ModuleConfig {
     // emscripten's ecc compiler, when used as the linker.
     pub obj_is_bitcode: bool,
     pub no_integrated_as: bool,
-    pub embed_bitcode: bool,
-    pub embed_bitcode_marker: bool,
+    pub embed_bitcode: EmbedBitcode,
 }
 
 impl ModuleConfig {
@@ -116,13 +122,11 @@ impl ModuleConfig {
             emit_pre_lto_bc: false,
             emit_bc: false,
             emit_bc_compressed: false,
-            emit_lto_bc: false,
             emit_ir: false,
             emit_asm: false,
             emit_obj: false,
             obj_is_bitcode: false,
-            embed_bitcode: false,
-            embed_bitcode_marker: false,
+            embed_bitcode: EmbedBitcode::None,
             no_integrated_as: false,
 
             verify_llvm_ir: false,
@@ -145,16 +149,15 @@ impl ModuleConfig {
         self.new_llvm_pass_manager = sess.opts.debugging_opts.new_llvm_pass_manager;
         self.obj_is_bitcode =
             sess.target.target.options.obj_is_bitcode || sess.opts.cg.linker_plugin_lto.enabled();
-        let embed_bitcode =
-            sess.target.target.options.embed_bitcode || sess.opts.debugging_opts.embed_bitcode;
-        if embed_bitcode {
-            match sess.opts.optimize {
-                config::OptLevel::No | config::OptLevel::Less => {
-                    self.embed_bitcode_marker = embed_bitcode;
+        self.embed_bitcode =
+            if sess.target.target.options.embed_bitcode || sess.opts.debugging_opts.embed_bitcode {
+                match sess.opts.optimize {
+                    config::OptLevel::No | config::OptLevel::Less => EmbedBitcode::Marker,
+                    _ => EmbedBitcode::Full,
                 }
-                _ => self.embed_bitcode = embed_bitcode,
-            }
-        }
+            } else {
+                EmbedBitcode::None
+            };
 
         // Copy what clang does by turning on loop vectorization at O2 and
         // slp vectorization at O3. Otherwise configure other optimization aspects
@@ -190,7 +193,10 @@ impl ModuleConfig {
     }
 
     pub fn bitcode_needed(&self) -> bool {
-        self.emit_bc || self.obj_is_bitcode || self.emit_bc_compressed || self.embed_bitcode
+        self.emit_bc
+            || self.obj_is_bitcode
+            || self.emit_bc_compressed
+            || self.embed_bitcode == EmbedBitcode::Full
     }
 }
 
@@ -379,7 +385,6 @@ pub fn start_async_codegen<B: ExtraBackendMethods>(
         modules_config.emit_no_opt_bc = true;
         modules_config.emit_pre_lto_bc = true;
         modules_config.emit_bc = true;
-        modules_config.emit_lto_bc = true;
         metadata_config.emit_bc = true;
         allocator_config.emit_bc = true;
     }
diff --git a/src/librustc_hir/def.rs b/src/librustc_hir/def.rs
index 696aa5c6f7dfe..3334cc32a52f7 100644
--- a/src/librustc_hir/def.rs
+++ b/src/librustc_hir/def.rs
@@ -159,6 +159,7 @@ impl DefKind {
     }
 }
 
+/// The resolution of a path or export.
 #[derive(Clone, Copy, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 #[derive(HashStable_Generic)]
 pub enum Res<Id = hir::HirId> {
diff --git a/src/librustc_infer/infer/mod.rs b/src/librustc_infer/infer/mod.rs
index fb00fbe28260d..dc494b8e41370 100644
--- a/src/librustc_infer/infer/mod.rs
+++ b/src/librustc_infer/infer/mod.rs
@@ -19,7 +19,7 @@ use rustc::traits::select;
 use rustc::ty::error::{ExpectedFound, TypeError, UnconstrainedNumeric};
 use rustc::ty::fold::{TypeFoldable, TypeFolder};
 use rustc::ty::relate::RelateResult;
-use rustc::ty::subst::{GenericArg, InternalSubsts, SubstsRef};
+use rustc::ty::subst::{GenericArg, GenericArgKind, InternalSubsts, SubstsRef};
 pub use rustc::ty::IntVarValue;
 use rustc::ty::{self, GenericParamDefKind, InferConst, Ty, TyCtxt};
 use rustc::ty::{ConstVid, FloatVid, IntVid, TyVid};
@@ -501,6 +501,7 @@ impl NLLRegionVariableOrigin {
     }
 }
 
+// FIXME(eddyb) investigate overlap between this and `TyOrConstInferVar`.
 #[derive(Copy, Clone, Debug)]
 pub enum FixupError<'tcx> {
     UnresolvedIntTy(IntVid),
@@ -1347,8 +1348,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     where
         T: TypeFoldable<'tcx>,
     {
-        let mut r = ShallowResolver::new(self);
-        value.fold_with(&mut r)
+        value.fold_with(&mut ShallowResolver { infcx: self })
     }
 
     pub fn root_var(&self, var: ty::TyVid) -> ty::TyVid {
@@ -1551,22 +1551,12 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         // variables, thus we don't need to substitute back the original values.
         self.tcx.const_eval_resolve(param_env, def_id, substs, promoted, span)
     }
-}
-
-pub struct ShallowResolver<'a, 'tcx> {
-    infcx: &'a InferCtxt<'a, 'tcx>,
-}
-
-impl<'a, 'tcx> ShallowResolver<'a, 'tcx> {
-    #[inline(always)]
-    pub fn new(infcx: &'a InferCtxt<'a, 'tcx>) -> Self {
-        ShallowResolver { infcx }
-    }
 
     /// If `typ` is a type variable of some kind, resolve it one level
     /// (but do not resolve types found in the result). If `typ` is
     /// not a type variable, just return it unmodified.
-    pub fn shallow_resolve(&mut self, typ: Ty<'tcx>) -> Ty<'tcx> {
+    // FIXME(eddyb) inline into `ShallowResolver::visit_ty`.
+    fn shallow_resolve_ty(&self, typ: Ty<'tcx>) -> Ty<'tcx> {
         match typ.kind {
             ty::Infer(ty::TyVar(v)) => {
                 // Not entirely obvious: if `typ` is a type variable,
@@ -1580,69 +1570,133 @@ impl<'a, 'tcx> ShallowResolver<'a, 'tcx> {
                 // depth.
                 //
                 // Note: if these two lines are combined into one we get
-                // dynamic borrow errors on `self.infcx.inner`.
-                let known = self.infcx.inner.borrow_mut().type_variables.probe(v).known();
-                known.map(|t| self.fold_ty(t)).unwrap_or(typ)
+                // dynamic borrow errors on `self.inner`.
+                let known = self.inner.borrow_mut().type_variables.probe(v).known();
+                known.map(|t| self.shallow_resolve_ty(t)).unwrap_or(typ)
             }
 
             ty::Infer(ty::IntVar(v)) => self
-                .infcx
                 .inner
                 .borrow_mut()
                 .int_unification_table
                 .probe_value(v)
-                .map(|v| v.to_type(self.infcx.tcx))
+                .map(|v| v.to_type(self.tcx))
                 .unwrap_or(typ),
 
             ty::Infer(ty::FloatVar(v)) => self
-                .infcx
                 .inner
                 .borrow_mut()
                 .float_unification_table
                 .probe_value(v)
-                .map(|v| v.to_type(self.infcx.tcx))
+                .map(|v| v.to_type(self.tcx))
                 .unwrap_or(typ),
 
             _ => typ,
         }
     }
 
-    // `resolver.shallow_resolve_changed(ty)` is equivalent to
-    // `resolver.shallow_resolve(ty) != ty`, but more efficient. It's always
-    // inlined, despite being large, because it has only two call sites that
-    // are extremely hot.
+    /// `ty_or_const_infer_var_changed` is equivalent to one of these two:
+    ///   * `shallow_resolve(ty) != ty` (where `ty.kind = ty::Infer(_)`)
+    ///   * `shallow_resolve(ct) != ct` (where `ct.kind = ty::ConstKind::Infer(_)`)
+    ///
+    /// However, `ty_or_const_infer_var_changed` is more efficient. It's always
+    /// inlined, despite being large, because it has only two call sites that
+    /// are extremely hot (both in `traits::fulfill`'s checking of `stalled_on`
+    /// inference variables), and it handles both `Ty` and `ty::Const` without
+    /// having to resort to storing full `GenericArg`s in `stalled_on`.
     #[inline(always)]
-    pub fn shallow_resolve_changed(&self, infer: ty::InferTy) -> bool {
-        match infer {
-            ty::TyVar(v) => {
+    pub fn ty_or_const_infer_var_changed(&self, infer_var: TyOrConstInferVar<'tcx>) -> bool {
+        match infer_var {
+            TyOrConstInferVar::Ty(v) => {
                 use self::type_variable::TypeVariableValue;
 
-                // If `inlined_probe` returns a `Known` value its `kind` never
-                // matches `infer`.
-                match self.infcx.inner.borrow_mut().type_variables.inlined_probe(v) {
+                // If `inlined_probe` returns a `Known` value, it never equals
+                // `ty::Infer(ty::TyVar(v))`.
+                match self.inner.borrow_mut().type_variables.inlined_probe(v) {
                     TypeVariableValue::Unknown { .. } => false,
                     TypeVariableValue::Known { .. } => true,
                 }
             }
 
-            ty::IntVar(v) => {
-                // If inlined_probe_value returns a value it's always a
+            TyOrConstInferVar::TyInt(v) => {
+                // If `inlined_probe_value` returns a value it's always a
                 // `ty::Int(_)` or `ty::UInt(_)`, which never matches a
                 // `ty::Infer(_)`.
-                self.infcx.inner.borrow_mut().int_unification_table.inlined_probe_value(v).is_some()
+                self.inner.borrow_mut().int_unification_table.inlined_probe_value(v).is_some()
             }
 
-            ty::FloatVar(v) => {
-                // If inlined_probe_value returns a value it's always a
+            TyOrConstInferVar::TyFloat(v) => {
+                // If `probe_value` returns a value it's always a
                 // `ty::Float(_)`, which never matches a `ty::Infer(_)`.
                 //
                 // Not `inlined_probe_value(v)` because this call site is colder.
-                self.infcx.inner.borrow_mut().float_unification_table.probe_value(v).is_some()
+                self.inner.borrow_mut().float_unification_table.probe_value(v).is_some()
             }
 
-            _ => unreachable!(),
+            TyOrConstInferVar::Const(v) => {
+                // If `probe_value` returns a `Known` value, it never equals
+                // `ty::ConstKind::Infer(ty::InferConst::Var(v))`.
+                //
+                // Not `inlined_probe_value(v)` because this call site is colder.
+                match self.inner.borrow_mut().const_unification_table.probe_value(v).val {
+                    ConstVariableValue::Unknown { .. } => false,
+                    ConstVariableValue::Known { .. } => true,
+                }
+            }
+        }
+    }
+}
+
+/// Helper for `ty_or_const_infer_var_changed` (see comment on that), currently
+/// used only for `traits::fulfill`'s list of `stalled_on` inference variables.
+#[derive(Copy, Clone, Debug)]
+pub enum TyOrConstInferVar<'tcx> {
+    /// Equivalent to `ty::Infer(ty::TyVar(_))`.
+    Ty(TyVid),
+    /// Equivalent to `ty::Infer(ty::IntVar(_))`.
+    TyInt(IntVid),
+    /// Equivalent to `ty::Infer(ty::FloatVar(_))`.
+    TyFloat(FloatVid),
+
+    /// Equivalent to `ty::ConstKind::Infer(ty::InferConst::Var(_))`.
+    Const(ConstVid<'tcx>),
+}
+
+impl TyOrConstInferVar<'tcx> {
+    /// Tries to extract an inference variable from a type or a constant, returns `None`
+    /// for types other than `ty::Infer(_)` (or `InferTy::Fresh*`) and
+    /// for constants other than `ty::ConstKind::Infer(_)` (or `InferConst::Fresh`).
+    pub fn maybe_from_generic_arg(arg: GenericArg<'tcx>) -> Option<Self> {
+        match arg.unpack() {
+            GenericArgKind::Type(ty) => Self::maybe_from_ty(ty),
+            GenericArgKind::Const(ct) => Self::maybe_from_const(ct),
+            GenericArgKind::Lifetime(_) => None,
         }
     }
+
+    /// Tries to extract an inference variable from a type, returns `None`
+    /// for types other than `ty::Infer(_)` (or `InferTy::Fresh*`).
+    pub fn maybe_from_ty(ty: Ty<'tcx>) -> Option<Self> {
+        match ty.kind {
+            ty::Infer(ty::TyVar(v)) => Some(TyOrConstInferVar::Ty(v)),
+            ty::Infer(ty::IntVar(v)) => Some(TyOrConstInferVar::TyInt(v)),
+            ty::Infer(ty::FloatVar(v)) => Some(TyOrConstInferVar::TyFloat(v)),
+            _ => None,
+        }
+    }
+
+    /// Tries to extract an inference variable from a constant, returns `None`
+    /// for constants other than `ty::ConstKind::Infer(_)` (or `InferConst::Fresh`).
+    pub fn maybe_from_const(ct: &'tcx ty::Const<'tcx>) -> Option<Self> {
+        match ct.val {
+            ty::ConstKind::Infer(InferConst::Var(v)) => Some(TyOrConstInferVar::Const(v)),
+            _ => None,
+        }
+    }
+}
+
+struct ShallowResolver<'a, 'tcx> {
+    infcx: &'a InferCtxt<'a, 'tcx>,
 }
 
 impl<'a, 'tcx> TypeFolder<'tcx> for ShallowResolver<'a, 'tcx> {
@@ -1651,7 +1705,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for ShallowResolver<'a, 'tcx> {
     }
 
     fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> {
-        self.shallow_resolve(ty)
+        self.infcx.shallow_resolve_ty(ty)
     }
 
     fn fold_const(&mut self, ct: &'tcx ty::Const<'tcx>) -> &'tcx ty::Const<'tcx> {
diff --git a/src/librustc_metadata/rmeta/decoder.rs b/src/librustc_metadata/rmeta/decoder.rs
index 4e086bcbb2d92..4520df588996e 100644
--- a/src/librustc_metadata/rmeta/decoder.rs
+++ b/src/librustc_metadata/rmeta/decoder.rs
@@ -509,14 +509,6 @@ impl<'a, 'tcx> SpecializedDecoder<Span> for DecodeContext<'a, 'tcx> {
     }
 }
 
-impl SpecializedDecoder<Ident> for DecodeContext<'_, '_> {
-    fn specialized_decode(&mut self) -> Result<Ident, Self::Error> {
-        // FIXME(jseyfried): intercrate hygiene
-
-        Ok(Ident::with_dummy_span(Symbol::decode(self)?))
-    }
-}
-
 impl<'a, 'tcx> SpecializedDecoder<Fingerprint> for DecodeContext<'a, 'tcx> {
     fn specialized_decode(&mut self) -> Result<Fingerprint, Self::Error> {
         Fingerprint::decode_opaque(&mut self.opaque)
@@ -663,15 +655,27 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
         &self.raw_proc_macros.unwrap()[pos]
     }
 
-    fn item_name(&self, item_index: DefIndex) -> Symbol {
+    fn item_ident(&self, item_index: DefIndex, sess: &Session) -> Ident {
         if !self.is_proc_macro(item_index) {
-            self.def_key(item_index)
+            let name = self
+                .def_key(item_index)
                 .disambiguated_data
                 .data
                 .get_opt_name()
-                .expect("no name in item_name")
+                .expect("no name in item_ident");
+            let span = self
+                .root
+                .per_def
+                .ident_span
+                .get(self, item_index)
+                .map(|data| data.decode((self, sess)))
+                .unwrap_or_else(|| panic!("Missing ident span for {:?} ({:?})", name, item_index));
+            Ident::new(name, span)
         } else {
-            Symbol::intern(self.raw_proc_macro(item_index).name())
+            Ident::new(
+                Symbol::intern(self.raw_proc_macro(item_index).name()),
+                self.get_span(item_index, sess),
+            )
         }
     }
 
@@ -750,6 +754,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
         kind: &EntryKind,
         index: DefIndex,
         parent_did: DefId,
+        sess: &Session,
     ) -> ty::VariantDef {
         let data = match kind {
             EntryKind::Variant(data) | EntryKind::Struct(data, _) | EntryKind::Union(data, _) => {
@@ -771,7 +776,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
 
         ty::VariantDef::new(
             tcx,
-            Ident::with_dummy_span(self.item_name(index)),
+            self.item_ident(index, sess),
             variant_did,
             ctor_did,
             data.discr,
@@ -783,7 +788,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
                 .decode(self)
                 .map(|index| ty::FieldDef {
                     did: self.local_def_id(index),
-                    ident: Ident::with_dummy_span(self.item_name(index)),
+                    ident: self.item_ident(index, sess),
                     vis: self.get_visibility(index),
                 })
                 .collect(),
@@ -812,10 +817,10 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
                 .get(self, item_id)
                 .unwrap_or(Lazy::empty())
                 .decode(self)
-                .map(|index| self.get_variant(tcx, &self.kind(index), index, did))
+                .map(|index| self.get_variant(tcx, &self.kind(index), index, did, tcx.sess))
                 .collect()
         } else {
-            std::iter::once(self.get_variant(tcx, &kind, item_id, did)).collect()
+            std::iter::once(self.get_variant(tcx, &kind, item_id, did, tcx.sess)).collect()
         };
 
         tcx.alloc_adt_def(did, adt_kind, variants, repr)
@@ -1007,7 +1012,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
                             if let Some(kind) = self.def_kind(child_index) {
                                 callback(Export {
                                     res: Res::Def(kind, self.local_def_id(child_index)),
-                                    ident: Ident::with_dummy_span(self.item_name(child_index)),
+                                    ident: self.item_ident(child_index, sess),
                                     vis: self.get_visibility(child_index),
                                     span: self
                                         .root
@@ -1028,10 +1033,11 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
 
                 let def_key = self.def_key(child_index);
                 let span = self.get_span(child_index, sess);
-                if let (Some(kind), Some(name)) =
-                    (self.def_kind(child_index), def_key.disambiguated_data.data.get_opt_name())
-                {
-                    let ident = Ident::with_dummy_span(name);
+                if let (Some(kind), true) = (
+                    self.def_kind(child_index),
+                    def_key.disambiguated_data.data.get_opt_name().is_some(),
+                ) {
+                    let ident = self.item_ident(child_index, sess);
                     let vis = self.get_visibility(child_index);
                     let def_id = self.local_def_id(child_index);
                     let res = Res::Def(kind, def_id);
@@ -1138,10 +1144,10 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
         }
     }
 
-    fn get_associated_item(&self, id: DefIndex) -> ty::AssocItem {
+    fn get_associated_item(&self, id: DefIndex, sess: &Session) -> ty::AssocItem {
         let def_key = self.def_key(id);
         let parent = self.local_def_id(def_key.parent.unwrap());
-        let name = def_key.disambiguated_data.data.get_opt_name().unwrap();
+        let ident = self.item_ident(id, sess);
 
         let (kind, container, has_self) = match self.kind(id) {
             EntryKind::AssocConst(container, _, _) => (ty::AssocKind::Const, container, false),
@@ -1155,7 +1161,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
         };
 
         ty::AssocItem {
-            ident: Ident::with_dummy_span(name),
+            ident,
             kind,
             vis: self.get_visibility(id),
             defaultness: container.defaultness(),
@@ -1219,7 +1225,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
             .get(self, id)
             .unwrap_or(Lazy::empty())
             .decode(self)
-            .map(|index| respan(self.get_span(index, sess), self.item_name(index)))
+            .map(|index| respan(self.get_span(index, sess), self.item_ident(index, sess).name))
             .collect()
     }
 
diff --git a/src/librustc_metadata/rmeta/decoder/cstore_impl.rs b/src/librustc_metadata/rmeta/decoder/cstore_impl.rs
index 1ac5caf138cc6..b9f1dd1663eee 100644
--- a/src/librustc_metadata/rmeta/decoder/cstore_impl.rs
+++ b/src/librustc_metadata/rmeta/decoder/cstore_impl.rs
@@ -110,7 +110,7 @@ provide! { <'tcx> tcx, def_id, other, cdata,
           |child| result.push(child.res.def_id()), tcx.sess);
         tcx.arena.alloc_slice(&result)
     }
-    associated_item => { cdata.get_associated_item(def_id.index) }
+    associated_item => { cdata.get_associated_item(def_id.index, tcx.sess) }
     impl_trait_ref => { cdata.get_impl_trait(def_id.index, tcx) }
     impl_polarity => { cdata.get_impl_polarity(def_id.index) }
     coerce_unsized_info => {
@@ -442,8 +442,8 @@ impl CStore {
         )
     }
 
-    pub fn associated_item_cloned_untracked(&self, def: DefId) -> ty::AssocItem {
-        self.get_crate_data(def.krate).get_associated_item(def.index)
+    pub fn associated_item_cloned_untracked(&self, def: DefId, sess: &Session) -> ty::AssocItem {
+        self.get_crate_data(def.krate).get_associated_item(def.index, sess)
     }
 
     pub fn crate_source_untracked(&self, cnum: CrateNum) -> CrateSource {
diff --git a/src/librustc_metadata/rmeta/encoder.rs b/src/librustc_metadata/rmeta/encoder.rs
index 52124fd3abb9b..9718d19281620 100644
--- a/src/librustc_metadata/rmeta/encoder.rs
+++ b/src/librustc_metadata/rmeta/encoder.rs
@@ -12,7 +12,7 @@ use rustc::traits::specialization_graph;
 use rustc::ty::codec::{self as ty_codec, TyEncoder};
 use rustc::ty::layout::VariantIdx;
 use rustc::ty::{self, SymbolName, Ty, TyCtxt};
-use rustc_ast::ast;
+use rustc_ast::ast::{self, Ident};
 use rustc_ast::attr;
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::FxHashMap;
@@ -30,7 +30,7 @@ use rustc_index::vec::Idx;
 use rustc_serialize::{opaque, Encodable, Encoder, SpecializedEncoder};
 use rustc_session::config::{self, CrateType};
 use rustc_span::source_map::Spanned;
-use rustc_span::symbol::{kw, sym, Ident, Symbol};
+use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::{self, ExternalSource, FileName, SourceFile, Span};
 use std::hash::Hash;
 use std::num::NonZeroUsize;
@@ -220,13 +220,6 @@ impl<'tcx> SpecializedEncoder<Span> for EncodeContext<'tcx> {
     }
 }
 
-impl SpecializedEncoder<Ident> for EncodeContext<'tcx> {
-    fn specialized_encode(&mut self, ident: &Ident) -> Result<(), Self::Error> {
-        // FIXME(jseyfried): intercrate hygiene
-        ident.name.encode(self)
-    }
-}
-
 impl<'tcx> SpecializedEncoder<LocalDefId> for EncodeContext<'tcx> {
     #[inline]
     fn specialized_encode(&mut self, def_id: &LocalDefId) -> Result<(), Self::Error> {
@@ -633,6 +626,7 @@ impl EncodeContext<'tcx> {
             assert!(f.did.is_local());
             f.did.index
         }));
+        self.encode_ident_span(def_id, variant.ident);
         self.encode_stability(def_id);
         self.encode_deprecation(def_id);
         self.encode_item_type(def_id);
@@ -735,6 +729,7 @@ impl EncodeContext<'tcx> {
         record!(self.per_def.visibility[def_id] <- field.vis);
         record!(self.per_def.span[def_id] <- self.tcx.def_span(def_id));
         record!(self.per_def.attributes[def_id] <- variant_data.fields()[field_index].attrs);
+        self.encode_ident_span(def_id, field.ident);
         self.encode_stability(def_id);
         self.encode_deprecation(def_id);
         self.encode_item_type(def_id);
@@ -869,6 +864,7 @@ impl EncodeContext<'tcx> {
         record!(self.per_def.visibility[def_id] <- trait_item.vis);
         record!(self.per_def.span[def_id] <- ast_item.span);
         record!(self.per_def.attributes[def_id] <- ast_item.attrs);
+        self.encode_ident_span(def_id, ast_item.ident);
         self.encode_stability(def_id);
         self.encode_const_stability(def_id);
         self.encode_deprecation(def_id);
@@ -952,6 +948,7 @@ impl EncodeContext<'tcx> {
         record!(self.per_def.visibility[def_id] <- impl_item.vis);
         record!(self.per_def.span[def_id] <- ast_item.span);
         record!(self.per_def.attributes[def_id] <- ast_item.attrs);
+        self.encode_ident_span(def_id, impl_item.ident);
         self.encode_stability(def_id);
         self.encode_const_stability(def_id);
         self.encode_deprecation(def_id);
@@ -1058,6 +1055,8 @@ impl EncodeContext<'tcx> {
 
         debug!("EncodeContext::encode_info_for_item({:?})", def_id);
 
+        self.encode_ident_span(def_id, item.ident);
+
         record!(self.per_def.kind[def_id] <- match item.kind {
             hir::ItemKind::Static(_, hir::Mutability::Mut, _) => EntryKind::MutStatic,
             hir::ItemKind::Static(_, hir::Mutability::Not, _) => EntryKind::ImmStatic,
@@ -1284,6 +1283,7 @@ impl EncodeContext<'tcx> {
         record!(self.per_def.visibility[def_id] <- ty::Visibility::Public);
         record!(self.per_def.span[def_id] <- macro_def.span);
         record!(self.per_def.attributes[def_id] <- macro_def.attrs);
+        self.encode_ident_span(def_id, macro_def.ident);
         self.encode_stability(def_id);
         self.encode_deprecation(def_id);
     }
@@ -1528,6 +1528,7 @@ impl EncodeContext<'tcx> {
             ty::Visibility::from_hir(&nitem.vis, nitem.hir_id, self.tcx));
         record!(self.per_def.span[def_id] <- nitem.span);
         record!(self.per_def.attributes[def_id] <- nitem.attrs);
+        self.encode_ident_span(def_id, nitem.ident);
         self.encode_stability(def_id);
         self.encode_const_stability(def_id);
         self.encode_deprecation(def_id);
@@ -1622,6 +1623,10 @@ impl EncodeContext<'tcx> {
         }
     }
 
+    fn encode_ident_span(&mut self, def_id: DefId, ident: Ident) {
+        record!(self.per_def.ident_span[def_id] <- ident.span);
+    }
+
     /// In some cases, along with the item itself, we also
     /// encode some sub-items. Usually we want some info from the item
     /// so it's easier to do that here then to wait until we would encounter
diff --git a/src/librustc_metadata/rmeta/mod.rs b/src/librustc_metadata/rmeta/mod.rs
index 448c1610c1368..3a4214e916acb 100644
--- a/src/librustc_metadata/rmeta/mod.rs
+++ b/src/librustc_metadata/rmeta/mod.rs
@@ -256,6 +256,7 @@ define_per_def_tables! {
     kind: Table<DefIndex, Lazy<EntryKind>>,
     visibility: Table<DefIndex, Lazy<ty::Visibility>>,
     span: Table<DefIndex, Lazy<Span>>,
+    ident_span: Table<DefIndex, Lazy<Span>>,
     attributes: Table<DefIndex, Lazy<[ast::Attribute]>>,
     children: Table<DefIndex, Lazy<[DefIndex]>>,
     stability: Table<DefIndex, Lazy<attr::Stability>>,
diff --git a/src/librustc_mir/transform/const_prop.rs b/src/librustc_mir/transform/const_prop.rs
index 8899f12b15361..548c637efb260 100644
--- a/src/librustc_mir/transform/const_prop.rs
+++ b/src/librustc_mir/transform/const_prop.rs
@@ -337,14 +337,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
     ) -> ConstPropagator<'mir, 'tcx> {
         let def_id = source.def_id();
         let substs = &InternalSubsts::identity_for_item(tcx, def_id);
-        let mut param_env = tcx.param_env(def_id);
-
-        // If we're evaluating inside a monomorphic function, then use `Reveal::All` because
-        // we want to see the same instances that codegen will see. This allows us to `resolve()`
-        // specializations.
-        if !substs.needs_subst() {
-            param_env = param_env.with_reveal_all();
-        }
+        let param_env = tcx.param_env(def_id).with_reveal_all();
 
         let span = tcx.def_span(def_id);
         let mut ecx = InterpCx::new(tcx.at(span), param_env, ConstPropMachine, ());
diff --git a/src/librustc_mir/transform/inline.rs b/src/librustc_mir/transform/inline.rs
index 52c7225a850fb..16c32e138fdf0 100644
--- a/src/librustc_mir/transform/inline.rs
+++ b/src/librustc_mir/transform/inline.rs
@@ -3,8 +3,8 @@
 use rustc::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use rustc::mir::visit::*;
 use rustc::mir::*;
-use rustc::ty::subst::{InternalSubsts, Subst, SubstsRef};
-use rustc::ty::{self, Instance, InstanceDef, ParamEnv, Ty, TyCtxt, TypeFoldable};
+use rustc::ty::subst::{Subst, SubstsRef};
+use rustc::ty::{self, Instance, InstanceDef, ParamEnv, Ty, TyCtxt};
 use rustc_attr as attr;
 use rustc_hir::def_id::DefId;
 use rustc_index::bit_set::BitSet;
@@ -66,14 +66,7 @@ impl Inliner<'tcx> {
 
         let mut callsites = VecDeque::new();
 
-        let mut param_env = self.tcx.param_env(self.source.def_id());
-
-        let substs = &InternalSubsts::identity_for_item(self.tcx, self.source.def_id());
-
-        // For monomorphic functions, we can use `Reveal::All` to resolve specialized instances.
-        if !substs.needs_subst() {
-            param_env = param_env.with_reveal_all();
-        }
+        let param_env = self.tcx.param_env(self.source.def_id()).with_reveal_all();
 
         // Only do inlining into fn bodies.
         let id = self.tcx.hir().as_local_hir_id(self.source.def_id()).unwrap();
diff --git a/src/librustc_mir_build/build/mod.rs b/src/librustc_mir_build/build/mod.rs
index d5daf465bb73d..a7ec4f501ae76 100644
--- a/src/librustc_mir_build/build/mod.rs
+++ b/src/librustc_mir_build/build/mod.rs
@@ -139,7 +139,8 @@ fn mir_build(tcx: TyCtxt<'_>, def_id: DefId) -> BodyAndCache<'_> {
             let arguments = implicit_argument.into_iter().chain(explicit_arguments);
 
             let (yield_ty, return_ty) = if body.generator_kind.is_some() {
-                let gen_sig = match ty.kind {
+                let gen_ty = tcx.body_tables(body_id).node_type(id);
+                let gen_sig = match gen_ty.kind {
                     ty::Generator(_, gen_substs, ..) => gen_substs.as_generator().sig(),
                     _ => span_bug!(tcx.hir().span(id), "generator w/o generator type: {:?}", ty),
                 };
diff --git a/src/librustc_resolve/build_reduced_graph.rs b/src/librustc_resolve/build_reduced_graph.rs
index db500a8b1fd5d..5408c85a4d006 100644
--- a/src/librustc_resolve/build_reduced_graph.rs
+++ b/src/librustc_resolve/build_reduced_graph.rs
@@ -904,7 +904,10 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                 self.insert_field_names(def_id, field_names);
             }
             Res::Def(DefKind::AssocFn, def_id) => {
-                if cstore.associated_item_cloned_untracked(def_id).method_has_self_argument {
+                if cstore
+                    .associated_item_cloned_untracked(def_id, self.r.session)
+                    .method_has_self_argument
+                {
                     self.r.has_self.insert(def_id);
                 }
             }
diff --git a/src/librustc_trait_selection/traits/fulfill.rs b/src/librustc_trait_selection/traits/fulfill.rs
index 865a4ba866ea9..0578c00fefb17 100644
--- a/src/librustc_trait_selection/traits/fulfill.rs
+++ b/src/librustc_trait_selection/traits/fulfill.rs
@@ -1,4 +1,4 @@
-use crate::infer::{InferCtxt, ShallowResolver};
+use crate::infer::{InferCtxt, TyOrConstInferVar};
 use rustc::ty::error::ExpectedFound;
 use rustc::ty::{self, ToPolyTraitRef, Ty, TypeFoldable};
 use rustc_data_structures::obligation_forest::ProcessResult;
@@ -73,7 +73,10 @@ pub struct FulfillmentContext<'tcx> {
 #[derive(Clone, Debug)]
 pub struct PendingPredicateObligation<'tcx> {
     pub obligation: PredicateObligation<'tcx>,
-    pub stalled_on: Vec<ty::InferTy>,
+    // FIXME(eddyb) look into whether this could be a `SmallVec`.
+    // Judging by the comment in `process_obligation`, the 1-element case
+    // is common so this could be a `SmallVec<[TyOrConstInferVar<'tcx>; 1]>`.
+    pub stalled_on: Vec<TyOrConstInferVar<'tcx>>,
 }
 
 // `PendingPredicateObligation` is used a lot. Make sure it doesn't unintentionally get bigger.
@@ -266,8 +269,8 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> {
             // Match arms are in order of frequency, which matters because this
             // code is so hot. 1 and 0 dominate; 2+ is fairly rare.
             1 => {
-                let infer = pending_obligation.stalled_on[0];
-                ShallowResolver::new(self.selcx.infcx()).shallow_resolve_changed(infer)
+                let infer_var = pending_obligation.stalled_on[0];
+                self.selcx.infcx().ty_or_const_infer_var_changed(infer_var)
             }
             0 => {
                 // In this case we haven't changed, but wish to make a change.
@@ -277,8 +280,8 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> {
                 // This `for` loop was once a call to `all()`, but this lower-level
                 // form was a perf win. See #64545 for details.
                 (|| {
-                    for &infer in &pending_obligation.stalled_on {
-                        if ShallowResolver::new(self.selcx.infcx()).shallow_resolve_changed(infer) {
+                    for &infer_var in &pending_obligation.stalled_on {
+                        if self.selcx.infcx().ty_or_const_infer_var_changed(infer_var) {
                             return true;
                         }
                     }
@@ -309,13 +312,6 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> {
 
         debug!("process_obligation: obligation = {:?} cause = {:?}", obligation, obligation.cause);
 
-        fn infer_ty(ty: Ty<'tcx>) -> ty::InferTy {
-            match ty.kind {
-                ty::Infer(infer) => infer,
-                _ => panic!(),
-            }
-        }
-
         match obligation.predicate {
             ty::Predicate::Trait(ref data, _) => {
                 let trait_obligation = obligation.with(data.clone());
@@ -467,7 +463,8 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> {
                     obligation.cause.span,
                 ) {
                     None => {
-                        pending_obligation.stalled_on = vec![infer_ty(ty)];
+                        pending_obligation.stalled_on =
+                            vec![TyOrConstInferVar::maybe_from_ty(ty).unwrap()];
                         ProcessResult::Unchanged
                     }
                     Some(os) => ProcessResult::Changed(mk_pending(os)),
@@ -483,8 +480,8 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> {
                     None => {
                         // None means that both are unresolved.
                         pending_obligation.stalled_on = vec![
-                            infer_ty(subtype.skip_binder().a),
-                            infer_ty(subtype.skip_binder().b),
+                            TyOrConstInferVar::maybe_from_ty(subtype.skip_binder().a).unwrap(),
+                            TyOrConstInferVar::maybe_from_ty(subtype.skip_binder().b).unwrap(),
                         ];
                         ProcessResult::Unchanged
                     }
@@ -534,20 +531,23 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> {
     }
 }
 
-/// Returns the set of type variables contained in a trait ref
+/// Returns the set of type inference variables contained in a trait ref.
 fn trait_ref_type_vars<'a, 'tcx>(
     selcx: &mut SelectionContext<'a, 'tcx>,
-    t: ty::PolyTraitRef<'tcx>,
-) -> Vec<ty::InferTy> {
-    t.skip_binder() // ok b/c this check doesn't care about regions
+    trait_ref: ty::PolyTraitRef<'tcx>,
+) -> Vec<TyOrConstInferVar<'tcx>> {
+    trait_ref
+        .skip_binder() // ok b/c this check doesn't care about regions
+        // FIXME(eddyb) walk over `GenericArg` to support const infer vars.
         .input_types()
-        .map(|t| selcx.infcx().resolve_vars_if_possible(&t))
-        .filter(|t| t.has_infer_types())
-        .flat_map(|t| t.walk())
-        .filter_map(|t| match t.kind {
-            ty::Infer(infer) => Some(infer),
-            _ => None,
-        })
+        .map(|ty| selcx.infcx().resolve_vars_if_possible(&ty))
+        // FIXME(eddyb) try using `maybe_walk` to skip *all* subtrees that
+        // don't contain inference variables, not just the outermost level.
+        // FIXME(eddyb) use `has_infer_types_or_const`.
+        .filter(|ty| ty.has_infer_types())
+        .flat_map(|ty| ty.walk())
+        // FIXME(eddyb) use `TyOrConstInferVar::maybe_from_generic_arg`.
+        .filter_map(TyOrConstInferVar::maybe_from_ty)
         .collect()
 }
 
diff --git a/src/librustc_ty/needs_drop.rs b/src/librustc_ty/needs_drop.rs
index 37af8168f87d9..f8149cdce4d30 100644
--- a/src/librustc_ty/needs_drop.rs
+++ b/src/librustc_ty/needs_drop.rs
@@ -99,6 +99,23 @@ where
                         }
                     }
 
+                    ty::Generator(_, substs, _) => {
+                        let substs = substs.as_generator();
+                        for upvar_ty in substs.upvar_tys() {
+                            queue_type(self, upvar_ty);
+                        }
+
+                        let witness = substs.witness();
+                        let interior_tys = match &witness.kind {
+                            ty::GeneratorWitness(tys) => tcx.erase_late_bound_regions(tys),
+                            _ => bug!(),
+                        };
+
+                        for interior_ty in interior_tys {
+                            queue_type(self, interior_ty);
+                        }
+                    }
+
                     // Check for a `Drop` impl and whether this is a union or
                     // `ManuallyDrop`. If it's a struct or enum without a `Drop`
                     // impl then check whether the field types need `Drop`.
diff --git a/src/librustc_typeck/collect/type_of.rs b/src/librustc_typeck/collect/type_of.rs
index 55642dfb4557b..30741ed53b58b 100644
--- a/src/librustc_typeck/collect/type_of.rs
+++ b/src/librustc_typeck/collect/type_of.rs
@@ -188,12 +188,12 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: DefId) -> Ty<'_> {
         Node::Field(field) => icx.to_ty(&field.ty),
 
         Node::Expr(&Expr { kind: ExprKind::Closure(.., gen), .. }) => {
-            if gen.is_some() {
-                return tcx.typeck_tables_of(def_id).node_type(hir_id);
-            }
-
             let substs = InternalSubsts::identity_for_item(tcx, def_id);
-            tcx.mk_closure(def_id, substs)
+            if let Some(movability) = gen {
+                tcx.mk_generator(def_id, substs, movability)
+            } else {
+                tcx.mk_closure(def_id, substs)
+            }
         }
 
         Node::AnonConst(_) => {
@@ -235,29 +235,31 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: DefId) -> Ty<'_> {
                     };
 
                     if let Some(path) = path {
-                        let arg_index = path
+                        // We've encountered an `AnonConst` in some path, so we need to
+                        // figure out which generic parameter it corresponds to and return
+                        // the relevant type.
+
+                        let (arg_index, segment) = path
                             .segments
                             .iter()
-                            .filter_map(|seg| seg.args.as_ref())
-                            .map(|generic_args| generic_args.args)
-                            .find_map(|args| {
+                            .filter_map(|seg| seg.args.as_ref().map(|args| (args.args, seg)))
+                            .find_map(|(args, seg)| {
                                 args.iter()
                                     .filter(|arg| arg.is_const())
                                     .enumerate()
                                     .filter(|(_, arg)| arg.id() == hir_id)
-                                    .map(|(index, _)| index)
+                                    .map(|(index, _)| (index, seg))
                                     .next()
                             })
                             .unwrap_or_else(|| {
                                 bug!("no arg matching AnonConst in path");
                             });
 
-                        // We've encountered an `AnonConst` in some path, so we need to
-                        // figure out which generic parameter it corresponds to and return
-                        // the relevant type.
-                        let generics = match path.res {
-                            Res::Def(DefKind::Ctor(..), def_id)
-                            | Res::Def(DefKind::AssocTy, def_id) => {
+                        // Try to use the segment resolution if it is valid, otherwise we
+                        // default to the path resolution.
+                        let res = segment.res.filter(|&r| r != Res::Err).unwrap_or(path.res);
+                        let generics = match res {
+                            Res::Def(DefKind::Ctor(..), def_id) => {
                                 tcx.generics_of(tcx.parent(def_id).unwrap())
                             }
                             Res::Def(_, def_id) => tcx.generics_of(def_id),
@@ -265,8 +267,8 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: DefId) -> Ty<'_> {
                                 tcx.sess.delay_span_bug(
                                     DUMMY_SP,
                                     &format!(
-                                        "unexpected const parent path def, parent: {:?}, def: {:?}",
-                                        parent_node, res
+                                        "unexpected anon const res {:?} in path: {:?}",
+                                        res, path,
                                     ),
                                 );
                                 return tcx.types.err;
@@ -291,8 +293,8 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: DefId) -> Ty<'_> {
                                 tcx.sess.delay_span_bug(
                                     DUMMY_SP,
                                     &format!(
-                                        "missing generic parameter for `AnonConst`, parent {:?}",
-                                        parent_node
+                                        "missing generic parameter for `AnonConst`, parent: {:?}, res: {:?}",
+                                        parent_node, res
                                     ),
                                 );
                                 tcx.types.err
diff --git a/src/librustc_typeck/lib.rs b/src/librustc_typeck/lib.rs
index e487e0d265c3e..fd854c750184e 100644
--- a/src/librustc_typeck/lib.rs
+++ b/src/librustc_typeck/lib.rs
@@ -62,6 +62,7 @@ This API is completely unstable and subject to change.
 #![feature(crate_visibility_modifier)]
 #![feature(in_band_lifetimes)]
 #![feature(nll)]
+#![feature(or_patterns)]
 #![feature(try_blocks)]
 #![feature(never_type)]
 #![feature(slice_partition_dedup)]
diff --git a/src/test/mir-opt/const_prop/control-flow-simplification.rs b/src/test/mir-opt/const_prop/control-flow-simplification.rs
new file mode 100644
index 0000000000000..0e9f33b15e2cc
--- /dev/null
+++ b/src/test/mir-opt/const_prop/control-flow-simplification.rs
@@ -0,0 +1,64 @@
+// compile-flags: -Zmir-opt-level=1
+
+trait NeedsDrop:Sized{
+    const NEEDS:bool=std::mem::needs_drop::<Self>();
+}
+
+impl<This> NeedsDrop for This{}
+
+fn hello<T>(){
+    if <bool>::NEEDS {
+        panic!()
+    }
+}
+
+pub fn main() {
+    hello::<()>();
+    hello::<Vec<()>>();
+}
+
+// END RUST SOURCE
+// START rustc.hello.ConstProp.before.mir
+// let mut _0: ();
+// let mut _1: bool;
+// let mut _2: !;
+// bb0: {
+//   StorageLive(_1);
+//   _1 = const <bool as NeedsDrop>::NEEDS;
+//   switchInt(_1) -> [false: bb1, otherwise: bb2];
+// }
+// bb1: {
+//   _0 = ();
+//   StorageDead(_1);
+//   return;
+// }
+// bb2: {
+//   StorageLive(_2);
+//   const std::rt::begin_panic::<&str>(const "explicit panic");
+// }
+// END rustc.hello.ConstProp.before.mir
+// START rustc.hello.ConstProp.after.mir
+// let mut _0: ();
+// let mut _1: bool;
+// let mut _2: !;
+// bb0: {
+//   StorageLive(_1);
+//   _1 = const false;
+//   switchInt(const false) -> [false: bb1, otherwise: bb2];
+// }
+// bb1: {
+//   _0 = ();
+//   StorageDead(_1);
+//   return;
+// }
+// bb2: {
+//   StorageLive(_2);
+//   const std::rt::begin_panic::<&str>(const "explicit panic");
+// }
+// END rustc.hello.ConstProp.after.mir
+// START rustc.hello.PreCodegen.before.mir
+// let mut _0: ();
+// bb0: {
+//   return;
+// }
+// END rustc.hello.PreCodegen.before.mir
diff --git a/src/test/mir-opt/generator-drop-cleanup.rs b/src/test/mir-opt/generator-drop-cleanup.rs
index 278dc49c92605..c4742e8156938 100644
--- a/src/test/mir-opt/generator-drop-cleanup.rs
+++ b/src/test/mir-opt/generator-drop-cleanup.rs
@@ -5,6 +5,7 @@
 
 fn main() {
     let gen = || {
+        let _s = String::new();
         yield;
     };
 }
@@ -13,35 +14,49 @@ fn main() {
 
 // START rustc.main-{{closure}}.generator_drop.0.mir
 // bb0: {
-//     _7 = discriminant((*_1));
-//     switchInt(move _7) -> [0u32: bb4, 3u32: bb7, otherwise: bb8];
+//     _9 = discriminant((*_1));
+//     switchInt(move _9) -> [0u32: bb7, 3u32: bb11, otherwise: bb12];
 // }
-// bb1: {
-//     StorageDead(_4);
-//     StorageDead(_3);
-//     goto -> bb5;
+// bb1 (cleanup): {
+//     resume;
 // }
-// bb2: {
-//     return;
+// bb2 (cleanup): {
+//     nop;
+//     goto -> bb8;
 // }
 // bb3: {
-//     return;
+//     StorageDead(_5);
+//     StorageDead(_4);
+//     drop((((*_1) as variant#3).0: std::string::String)) -> [return: bb4, unwind: bb2];
 // }
 // bb4: {
-//     goto -> bb6;
+//     nop;
+//     goto -> bb9;
 // }
 // bb5: {
-//     goto -> bb2;
+//     return;
 // }
 // bb6: {
-//     goto -> bb3;
+//     return;
 // }
 // bb7: {
-//     StorageLive(_3);
-//     StorageLive(_4);
+//     goto -> bb10;
+// }
+// bb8 (cleanup): {
 //     goto -> bb1;
 // }
-// bb8: {
+// bb9: {
+//     goto -> bb5;
+// }
+// bb10: {
+//     goto -> bb6;
+// }
+// bb11: {
+//     StorageLive(_4);
+//     StorageLive(_5);
+//     goto -> bb3;
+// }
+// bb12: {
 //     return;
 // }
 // END rustc.main-{{closure}}.generator_drop.0.mir
diff --git a/src/test/ui/async-await/async-block-control-flow-static-semantics.stderr b/src/test/ui/async-await/async-block-control-flow-static-semantics.stderr
index afb8f146192cc..46a132da309bb 100644
--- a/src/test/ui/async-await/async-block-control-flow-static-semantics.stderr
+++ b/src/test/ui/async-await/async-block-control-flow-static-semantics.stderr
@@ -18,22 +18,6 @@ LL | |             break 0u8;
 LL | |         };
    | |_________- enclosing `async` block
 
-error[E0308]: mismatched types
-  --> $DIR/async-block-control-flow-static-semantics.rs:13:43
-   |
-LL | fn return_targets_async_block_not_fn() -> u8 {
-   |    ---------------------------------      ^^ expected `u8`, found `()`
-   |    |
-   |    implicitly returns `()` as its body has no tail or `return` expression
-
-error[E0271]: type mismatch resolving `<impl std::future::Future as std::future::Future>::Output == ()`
-  --> $DIR/async-block-control-flow-static-semantics.rs:18:39
-   |
-LL |     let _: &dyn Future<Output = ()> = &block;
-   |                                       ^^^^^^ expected `()`, found `u8`
-   |
-   = note: required for the cast to the object type `dyn std::future::Future<Output = ()>`
-
 error[E0308]: mismatched types
   --> $DIR/async-block-control-flow-static-semantics.rs:22:58
    |
@@ -55,6 +39,22 @@ LL |     let _: &dyn Future<Output = ()> = &block;
    |
    = note: required for the cast to the object type `dyn std::future::Future<Output = ()>`
 
+error[E0308]: mismatched types
+  --> $DIR/async-block-control-flow-static-semantics.rs:13:43
+   |
+LL | fn return_targets_async_block_not_fn() -> u8 {
+   |    ---------------------------------      ^^ expected `u8`, found `()`
+   |    |
+   |    implicitly returns `()` as its body has no tail or `return` expression
+
+error[E0271]: type mismatch resolving `<impl std::future::Future as std::future::Future>::Output == ()`
+  --> $DIR/async-block-control-flow-static-semantics.rs:18:39
+   |
+LL |     let _: &dyn Future<Output = ()> = &block;
+   |                                       ^^^^^^ expected `()`, found `u8`
+   |
+   = note: required for the cast to the object type `dyn std::future::Future<Output = ()>`
+
 error[E0308]: mismatched types
   --> $DIR/async-block-control-flow-static-semantics.rs:48:44
    |
diff --git a/src/test/ui/async-await/async-error-span.rs b/src/test/ui/async-await/async-error-span.rs
index 28132c9789c67..cf10ebfeca939 100644
--- a/src/test/ui/async-await/async-error-span.rs
+++ b/src/test/ui/async-await/async-error-span.rs
@@ -5,6 +5,7 @@
 use std::future::Future;
 
 fn get_future() -> impl Future<Output = ()> {
+//~^ ERROR the trait bound `(): std::future::Future` is not satisfied
     panic!()
 }
 
diff --git a/src/test/ui/async-await/async-error-span.stderr b/src/test/ui/async-await/async-error-span.stderr
index b551b99587dd9..4054e739c483d 100644
--- a/src/test/ui/async-await/async-error-span.stderr
+++ b/src/test/ui/async-await/async-error-span.stderr
@@ -1,15 +1,27 @@
+error[E0277]: the trait bound `(): std::future::Future` is not satisfied
+  --> $DIR/async-error-span.rs:7:20
+   |
+LL | fn get_future() -> impl Future<Output = ()> {
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^^ the trait `std::future::Future` is not implemented for `()`
+LL |
+LL |     panic!()
+   |     -------- this returned value is of type `!`
+   |
+   = note: the return type of a function must have a statically known size
+
 error[E0698]: type inside `async fn` body must be known in this context
-  --> $DIR/async-error-span.rs:12:9
+  --> $DIR/async-error-span.rs:13:9
    |
 LL |     let a;
    |         ^ cannot infer type
    |
 note: the type is part of the `async fn` body because of this `await`
-  --> $DIR/async-error-span.rs:13:5
+  --> $DIR/async-error-span.rs:14:5
    |
 LL |     get_future().await;
    |     ^^^^^^^^^^^^^^^^^^
 
-error: aborting due to previous error
+error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0698`.
+Some errors have detailed explanations: E0277, E0698.
+For more information about an error, try `rustc --explain E0277`.
diff --git a/src/test/ui/async-await/await-keyword/incorrect-syntax-suggestions.rs b/src/test/ui/async-await/await-keyword/incorrect-syntax-suggestions.rs
index 22bcbb1064dd7..cebff3be6b059 100644
--- a/src/test/ui/async-await/await-keyword/incorrect-syntax-suggestions.rs
+++ b/src/test/ui/async-await/await-keyword/incorrect-syntax-suggestions.rs
@@ -62,6 +62,7 @@ fn foo10() -> Result<(), ()> {
 fn foo11() -> Result<(), ()> {
     let _ = await bar()?; //~ ERROR `await` is only allowed inside `async` functions and blocks
     //~^ ERROR incorrect use of `await`
+    //~| ERROR the `?` operator can only be applied to values that implement `std::ops::Try`
     Ok(())
 }
 fn foo12() -> Result<(), ()> {
diff --git a/src/test/ui/async-await/await-keyword/incorrect-syntax-suggestions.stderr b/src/test/ui/async-await/await-keyword/incorrect-syntax-suggestions.stderr
index 92cef80c19360..61f2570b2ff93 100644
--- a/src/test/ui/async-await/await-keyword/incorrect-syntax-suggestions.stderr
+++ b/src/test/ui/async-await/await-keyword/incorrect-syntax-suggestions.stderr
@@ -71,49 +71,49 @@ LL |     let _ = await bar()?;
    |             ^^^^^^^^^^^^ help: `await` is a postfix operation: `bar()?.await`
 
 error: incorrect use of `await`
-  --> $DIR/incorrect-syntax-suggestions.rs:68:14
+  --> $DIR/incorrect-syntax-suggestions.rs:69:14
    |
 LL |     let _ = (await bar())?;
    |              ^^^^^^^^^^^ help: `await` is a postfix operation: `bar().await`
 
 error: incorrect use of `await`
-  --> $DIR/incorrect-syntax-suggestions.rs:73:24
+  --> $DIR/incorrect-syntax-suggestions.rs:74:24
    |
 LL |     let _ = bar().await();
    |                        ^^ help: `await` is not a method call, remove the parentheses
 
 error: incorrect use of `await`
-  --> $DIR/incorrect-syntax-suggestions.rs:78:24
+  --> $DIR/incorrect-syntax-suggestions.rs:79:24
    |
 LL |     let _ = bar().await()?;
    |                        ^^ help: `await` is not a method call, remove the parentheses
 
 error: incorrect use of `await`
-  --> $DIR/incorrect-syntax-suggestions.rs:106:13
+  --> $DIR/incorrect-syntax-suggestions.rs:107:13
    |
 LL |     let _ = await!(bar());
    |             ^^^^^^^^^^^^^ help: `await` is a postfix operation: `bar().await`
 
 error: incorrect use of `await`
-  --> $DIR/incorrect-syntax-suggestions.rs:110:13
+  --> $DIR/incorrect-syntax-suggestions.rs:111:13
    |
 LL |     let _ = await!(bar())?;
    |             ^^^^^^^^^^^^^ help: `await` is a postfix operation: `bar().await`
 
 error: incorrect use of `await`
-  --> $DIR/incorrect-syntax-suggestions.rs:115:17
+  --> $DIR/incorrect-syntax-suggestions.rs:116:17
    |
 LL |         let _ = await!(bar())?;
    |                 ^^^^^^^^^^^^^ help: `await` is a postfix operation: `bar().await`
 
 error: incorrect use of `await`
-  --> $DIR/incorrect-syntax-suggestions.rs:123:17
+  --> $DIR/incorrect-syntax-suggestions.rs:124:17
    |
 LL |         let _ = await!(bar())?;
    |                 ^^^^^^^^^^^^^ help: `await` is a postfix operation: `bar().await`
 
 error: expected expression, found `=>`
-  --> $DIR/incorrect-syntax-suggestions.rs:131:25
+  --> $DIR/incorrect-syntax-suggestions.rs:132:25
    |
 LL |     match await { await => () }
    |                   ----- ^^ expected expression
@@ -121,13 +121,13 @@ LL |     match await { await => () }
    |                   while parsing this incorrect await expression
 
 error: incorrect use of `await`
-  --> $DIR/incorrect-syntax-suggestions.rs:131:11
+  --> $DIR/incorrect-syntax-suggestions.rs:132:11
    |
 LL |     match await { await => () }
    |           ^^^^^^^^^^^^^^^^^^^^^ help: `await` is a postfix operation: `{ await => () }.await`
 
 error: expected one of `.`, `?`, `{`, or an operator, found `}`
-  --> $DIR/incorrect-syntax-suggestions.rs:134:1
+  --> $DIR/incorrect-syntax-suggestions.rs:135:1
    |
 LL |     match await { await => () }
    |     -----                      - expected one of `.`, `?`, `{`, or an operator
@@ -162,7 +162,7 @@ LL |     let _ = await bar()?;
    |             ^^^^^^^^^^^^ only allowed inside `async` functions and blocks
 
 error[E0728]: `await` is only allowed inside `async` functions and blocks
-  --> $DIR/incorrect-syntax-suggestions.rs:68:14
+  --> $DIR/incorrect-syntax-suggestions.rs:69:14
    |
 LL | fn foo12() -> Result<(), ()> {
    |    ----- this is not `async`
@@ -170,7 +170,7 @@ LL |     let _ = (await bar())?;
    |              ^^^^^^^^^^^ only allowed inside `async` functions and blocks
 
 error[E0728]: `await` is only allowed inside `async` functions and blocks
-  --> $DIR/incorrect-syntax-suggestions.rs:73:13
+  --> $DIR/incorrect-syntax-suggestions.rs:74:13
    |
 LL | fn foo13() -> Result<(), ()> {
    |    ----- this is not `async`
@@ -178,7 +178,7 @@ LL |     let _ = bar().await();
    |             ^^^^^^^^^^^ only allowed inside `async` functions and blocks
 
 error[E0728]: `await` is only allowed inside `async` functions and blocks
-  --> $DIR/incorrect-syntax-suggestions.rs:78:13
+  --> $DIR/incorrect-syntax-suggestions.rs:79:13
    |
 LL | fn foo14() -> Result<(), ()> {
    |    ----- this is not `async`
@@ -186,7 +186,7 @@ LL |     let _ = bar().await()?;
    |             ^^^^^^^^^^^ only allowed inside `async` functions and blocks
 
 error[E0728]: `await` is only allowed inside `async` functions and blocks
-  --> $DIR/incorrect-syntax-suggestions.rs:83:13
+  --> $DIR/incorrect-syntax-suggestions.rs:84:13
    |
 LL | fn foo15() -> Result<(), ()> {
    |    ----- this is not `async`
@@ -194,7 +194,7 @@ LL |     let _ = bar().await;
    |             ^^^^^^^^^^^ only allowed inside `async` functions and blocks
 
 error[E0728]: `await` is only allowed inside `async` functions and blocks
-  --> $DIR/incorrect-syntax-suggestions.rs:87:13
+  --> $DIR/incorrect-syntax-suggestions.rs:88:13
    |
 LL | fn foo16() -> Result<(), ()> {
    |    ----- this is not `async`
@@ -202,7 +202,7 @@ LL |     let _ = bar().await?;
    |             ^^^^^^^^^^^ only allowed inside `async` functions and blocks
 
 error[E0728]: `await` is only allowed inside `async` functions and blocks
-  --> $DIR/incorrect-syntax-suggestions.rs:92:17
+  --> $DIR/incorrect-syntax-suggestions.rs:93:17
    |
 LL |     fn foo() -> Result<(), ()> {
    |        --- this is not `async`
@@ -210,7 +210,7 @@ LL |         let _ = bar().await?;
    |                 ^^^^^^^^^^^ only allowed inside `async` functions and blocks
 
 error[E0728]: `await` is only allowed inside `async` functions and blocks
-  --> $DIR/incorrect-syntax-suggestions.rs:99:17
+  --> $DIR/incorrect-syntax-suggestions.rs:100:17
    |
 LL |     let foo = || {
    |               -- this is not `async`
@@ -218,7 +218,7 @@ LL |         let _ = bar().await?;
    |                 ^^^^^^^^^^^ only allowed inside `async` functions and blocks
 
 error[E0728]: `await` is only allowed inside `async` functions and blocks
-  --> $DIR/incorrect-syntax-suggestions.rs:115:17
+  --> $DIR/incorrect-syntax-suggestions.rs:116:17
    |
 LL |     fn foo() -> Result<(), ()> {
    |        --- this is not `async`
@@ -226,7 +226,7 @@ LL |         let _ = await!(bar())?;
    |                 ^^^^^^^^^^^^^ only allowed inside `async` functions and blocks
 
 error[E0728]: `await` is only allowed inside `async` functions and blocks
-  --> $DIR/incorrect-syntax-suggestions.rs:123:17
+  --> $DIR/incorrect-syntax-suggestions.rs:124:17
    |
 LL |     let foo = || {
    |               -- this is not `async`
@@ -242,7 +242,16 @@ LL |     let _ = await bar()?;
    = help: the trait `std::ops::Try` is not implemented for `impl std::future::Future`
    = note: required by `std::ops::Try::into_result`
 
-error: aborting due to 35 previous errors
+error[E0277]: the `?` operator can only be applied to values that implement `std::ops::Try`
+  --> $DIR/incorrect-syntax-suggestions.rs:63:19
+   |
+LL |     let _ = await bar()?;
+   |                   ^^^^^^ the `?` operator cannot be applied to type `impl std::future::Future`
+   |
+   = help: the trait `std::ops::Try` is not implemented for `impl std::future::Future`
+   = note: required by `std::ops::Try::into_result`
+
+error: aborting due to 36 previous errors
 
 Some errors have detailed explanations: E0277, E0728.
 For more information about an error, try `rustc --explain E0277`.
diff --git a/src/test/ui/async-await/issue-67651.rs b/src/test/ui/async-await/issue-67651.rs
new file mode 100644
index 0000000000000..bd96a3b709bae
--- /dev/null
+++ b/src/test/ui/async-await/issue-67651.rs
@@ -0,0 +1,20 @@
+// edition:2018
+
+trait From {
+    fn from();
+}
+
+impl From for () {
+    fn from() {}
+}
+
+impl From for () {
+//~^ ERROR conflicting implementations of trait
+    fn from() {}
+}
+
+fn bar() -> impl core::future::Future<Output = ()> {
+    async move { From::from() }
+}
+
+fn main() {}
diff --git a/src/test/ui/async-await/issue-67651.stderr b/src/test/ui/async-await/issue-67651.stderr
new file mode 100644
index 0000000000000..99857c215eb8f
--- /dev/null
+++ b/src/test/ui/async-await/issue-67651.stderr
@@ -0,0 +1,12 @@
+error[E0119]: conflicting implementations of trait `From` for type `()`:
+  --> $DIR/issue-67651.rs:11:1
+   |
+LL | impl From for () {
+   | ---------------- first implementation here
+...
+LL | impl From for () {
+   | ^^^^^^^^^^^^^^^^ conflicting implementation for `()`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0119`.
diff --git a/src/test/ui/async-await/issues/issue-63388-2.nll.stderr b/src/test/ui/async-await/issues/issue-63388-2.nll.stderr
deleted file mode 100644
index 6edb9e63d480a..0000000000000
--- a/src/test/ui/async-await/issues/issue-63388-2.nll.stderr
+++ /dev/null
@@ -1,13 +0,0 @@
-error[E0106]: missing lifetime specifier
-  --> $DIR/issue-63388-2.rs:12:10
-   |
-LL |         foo: &dyn Foo, bar: &'a dyn Foo
-   |              --------       -----------
-LL |     ) -> &dyn Foo
-   |          ^ help: consider using the named lifetime: `&'a`
-   |
-   = help: this function's return type contains a borrowed value, but the signature does not say whether it is borrowed from `foo` or `bar`
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0106`.
diff --git a/src/test/ui/async-await/issues/issue-63388-2.rs b/src/test/ui/async-await/issues/issue-63388-2.rs
index 73e7f25f97d0d..458bc9faeaf27 100644
--- a/src/test/ui/async-await/issues/issue-63388-2.rs
+++ b/src/test/ui/async-await/issues/issue-63388-2.rs
@@ -8,7 +8,7 @@ trait Foo {}
 
 impl Xyz {
     async fn do_sth<'a>(
-        foo: &dyn Foo, bar: &'a dyn Foo //~ ERROR cannot infer
+        foo: &dyn Foo, bar: &'a dyn Foo
     ) -> &dyn Foo //~ ERROR missing lifetime specifier
     {
         foo
diff --git a/src/test/ui/async-await/issues/issue-63388-2.stderr b/src/test/ui/async-await/issues/issue-63388-2.stderr
index 9f51ced9c3f49..6edb9e63d480a 100644
--- a/src/test/ui/async-await/issues/issue-63388-2.stderr
+++ b/src/test/ui/async-await/issues/issue-63388-2.stderr
@@ -8,21 +8,6 @@ LL |     ) -> &dyn Foo
    |
    = help: this function's return type contains a borrowed value, but the signature does not say whether it is borrowed from `foo` or `bar`
 
-error: cannot infer an appropriate lifetime
-  --> $DIR/issue-63388-2.rs:11:9
-   |
-LL |         foo: &dyn Foo, bar: &'a dyn Foo
-   |         ^^^ ...but this borrow...
-...
-LL |         foo
-   |         --- this return type evaluates to the `'static` lifetime...
-   |
-note: ...can't outlive the lifetime `'_` as defined on the method body at 11:14
-  --> $DIR/issue-63388-2.rs:11:14
-   |
-LL |         foo: &dyn Foo, bar: &'a dyn Foo
-   |              ^
-
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0106`.
diff --git a/src/test/ui/async-await/issues/issue-65159.rs b/src/test/ui/async-await/issues/issue-65159.rs
index b5fee061f277e..2f80435046bdf 100644
--- a/src/test/ui/async-await/issues/issue-65159.rs
+++ b/src/test/ui/async-await/issues/issue-65159.rs
@@ -5,6 +5,7 @@
 async fn copy() -> Result<()> //~ ERROR wrong number of type arguments
 {
     Ok(())
+    //~^ type annotations needed
 }
 
 fn main() { }
diff --git a/src/test/ui/async-await/issues/issue-65159.stderr b/src/test/ui/async-await/issues/issue-65159.stderr
index 56d2c38b302e9..04cfa5249982e 100644
--- a/src/test/ui/async-await/issues/issue-65159.stderr
+++ b/src/test/ui/async-await/issues/issue-65159.stderr
@@ -4,6 +4,13 @@ error[E0107]: wrong number of type arguments: expected 2, found 1
 LL | async fn copy() -> Result<()>
    |                    ^^^^^^^^^^ expected 2 type arguments
 
-error: aborting due to previous error
+error[E0282]: type annotations needed
+  --> $DIR/issue-65159.rs:7:5
+   |
+LL |     Ok(())
+   |     ^^ cannot infer type for type parameter `E` declared on the enum `Result`
+
+error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0107`.
+Some errors have detailed explanations: E0107, E0282.
+For more information about an error, try `rustc --explain E0107`.
diff --git a/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-no-fg.rs b/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-no-fg.rs
index b12d7bccecead..05960c0c7f636 100644
--- a/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-no-fg.rs
+++ b/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-no-fg.rs
@@ -9,6 +9,9 @@ impl<T> Trait<'_, '_> for T { }
 async fn async_ret_impl_trait<'a, 'b>(a: &'a u8, b: &'b u8) -> impl Trait<'a, 'b> {
     //~^ ERROR ambiguous lifetime bound
     //~| ERROR ambiguous lifetime bound
+    //~| ERROR ambiguous lifetime bound
+    //~| ERROR hidden type for `impl Trait` captures lifetime that does not appear in bounds
+    //~| ERROR hidden type for `impl Trait` captures lifetime that does not appear in bounds
     (a, b)
 }
 
diff --git a/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-no-fg.stderr b/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-no-fg.stderr
index f9a1b4b3394c1..c69595a3f4d01 100644
--- a/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-no-fg.stderr
+++ b/src/test/ui/async-await/multiple-lifetimes/ret-impl-trait-no-fg.stderr
@@ -14,5 +14,42 @@ LL | async fn async_ret_impl_trait<'a, 'b>(a: &'a u8, b: &'b u8) -> impl Trait<'
    |
    = help: add #![feature(member_constraints)] to the crate attributes to enable
 
-error: aborting due to 2 previous errors
+error: ambiguous lifetime bound in `impl Trait`
+  --> $DIR/ret-impl-trait-no-fg.rs:9:64
+   |
+LL | async fn async_ret_impl_trait<'a, 'b>(a: &'a u8, b: &'b u8) -> impl Trait<'a, 'b> {
+   |                                                                ^^^^^^^^^^^^^^^^^^ the elided lifetimes here do not outlive one another
+   |
+   = help: add #![feature(member_constraints)] to the crate attributes to enable
+
+error[E0700]: hidden type for `impl Trait` captures lifetime that does not appear in bounds
+  --> $DIR/ret-impl-trait-no-fg.rs:9:1
+   |
+LL | / async fn async_ret_impl_trait<'a, 'b>(a: &'a u8, b: &'b u8) -> impl Trait<'a, 'b> {
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     (a, b)
+LL | | }
+   | |_^
+   |
+   = note: hidden type `(&u8, &u8)` captures lifetime '_#4r
+
+error[E0700]: hidden type for `impl Trait` captures lifetime that does not appear in bounds
+  --> $DIR/ret-impl-trait-no-fg.rs:9:1
+   |
+LL | / async fn async_ret_impl_trait<'a, 'b>(a: &'a u8, b: &'b u8) -> impl Trait<'a, 'b> {
+LL | |
+LL | |
+LL | |
+...  |
+LL | |     (a, b)
+LL | | }
+   | |_^
+   |
+   = note: hidden type `(&u8, &u8)` captures lifetime '_#5r
+
+error: aborting due to 5 previous errors
 
+For more information about this error, try `rustc --explain E0700`.
diff --git a/src/test/ui/const-generics/issues/issue70273-assoc-fn.rs b/src/test/ui/const-generics/issues/issue70273-assoc-fn.rs
new file mode 100644
index 0000000000000..a192ddea9c6ab
--- /dev/null
+++ b/src/test/ui/const-generics/issues/issue70273-assoc-fn.rs
@@ -0,0 +1,17 @@
+// check-pass
+
+#![feature(const_generics)]
+//~^ WARN the feature `const_generics` is incomplete and may cause the compiler to crash
+
+trait T<const A: usize> {
+    fn f();
+}
+struct S;
+
+impl T<0usize> for S {
+    fn f() {}
+}
+
+fn main() {
+    let _err = <S as T<0usize>>::f();
+}
diff --git a/src/test/ui/const-generics/issues/issue70273-assoc-fn.stderr b/src/test/ui/const-generics/issues/issue70273-assoc-fn.stderr
new file mode 100644
index 0000000000000..64007ade0f2ed
--- /dev/null
+++ b/src/test/ui/const-generics/issues/issue70273-assoc-fn.stderr
@@ -0,0 +1,8 @@
+warning: the feature `const_generics` is incomplete and may cause the compiler to crash
+  --> $DIR/issue70273-assoc-fn.rs:3:12
+   |
+LL | #![feature(const_generics)]
+   |            ^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+
diff --git a/src/test/ui/const-generics/type_of_anon_const.rs b/src/test/ui/const-generics/type_of_anon_const.rs
new file mode 100644
index 0000000000000..776084b77a577
--- /dev/null
+++ b/src/test/ui/const-generics/type_of_anon_const.rs
@@ -0,0 +1,21 @@
+// run-pass
+
+#![feature(const_generics)]
+//~^ WARN the feature `const_generics` is incomplete and may cause the compiler to crash
+
+trait T<const A: usize> {
+    fn l<const N: bool>() -> usize;
+    fn r<const N: bool>() -> bool;
+}
+
+struct S;
+
+impl<const N: usize> T<N> for S {
+    fn l<const M: bool>() -> usize { N }
+    fn r<const M: bool>() -> bool { M }
+}
+
+fn main() {
+   assert_eq!(<S as T<123>>::l::<true>(), 123);
+   assert!(<S as T<123>>::r::<true>());
+}
diff --git a/src/test/ui/const-generics/type_of_anon_const.stderr b/src/test/ui/const-generics/type_of_anon_const.stderr
new file mode 100644
index 0000000000000..495d34ce09b81
--- /dev/null
+++ b/src/test/ui/const-generics/type_of_anon_const.stderr
@@ -0,0 +1,8 @@
+warning: the feature `const_generics` is incomplete and may cause the compiler to crash
+  --> $DIR/type_of_anon_const.rs:3:12
+   |
+LL | #![feature(const_generics)]
+   |            ^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+
diff --git a/src/test/ui/copy-a-resource.rs b/src/test/ui/copy-a-resource.rs
index 55f2dd4ee6dde..1a647692018e5 100644
--- a/src/test/ui/copy-a-resource.rs
+++ b/src/test/ui/copy-a-resource.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 #[derive(Debug)]
 struct Foo {
   i: isize,
diff --git a/src/test/ui/copy-a-resource.stderr b/src/test/ui/copy-a-resource.stderr
index c95e8d239d2b9..71d2eead3554c 100644
--- a/src/test/ui/copy-a-resource.stderr
+++ b/src/test/ui/copy-a-resource.stderr
@@ -1,11 +1,19 @@
 error[E0599]: no method named `clone` found for struct `Foo` in the current scope
-  --> $DIR/copy-a-resource.rs:18:16
+  --> $DIR/copy-a-resource.rs:23:16
    |
 LL | struct Foo {
    | ---------- method `clone` not found for this
 ...
 LL |     let _y = x.clone();
    |                ^^^^^ method not found in `Foo`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<Foo>` here
+   |        the method is available for `std::rc::Rc<Foo>` here
    |
    = help: items from traits can only be used if the trait is implemented and in scope
    = note: the following trait defines an item `clone`, perhaps you need to implement it:
diff --git a/src/test/ui/derives/derive-assoc-type-not-impl.rs b/src/test/ui/derives/derive-assoc-type-not-impl.rs
index 0f642d63a1dcb..fa5afd2419261 100644
--- a/src/test/ui/derives/derive-assoc-type-not-impl.rs
+++ b/src/test/ui/derives/derive-assoc-type-not-impl.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 trait Foo {
     type X;
     fn method(&self) {}
diff --git a/src/test/ui/derives/derive-assoc-type-not-impl.stderr b/src/test/ui/derives/derive-assoc-type-not-impl.stderr
index c4c85773fbc1d..f15aba97ded81 100644
--- a/src/test/ui/derives/derive-assoc-type-not-impl.stderr
+++ b/src/test/ui/derives/derive-assoc-type-not-impl.stderr
@@ -1,5 +1,5 @@
 error[E0599]: no method named `clone` found for struct `Bar<NotClone>` in the current scope
-  --> $DIR/derive-assoc-type-not-impl.rs:18:30
+  --> $DIR/derive-assoc-type-not-impl.rs:23:30
    |
 LL | struct Bar<T: Foo> {
    | ------------------
@@ -12,6 +12,14 @@ LL | struct NotClone;
 ...
 LL |     Bar::<NotClone> { x: 1 }.clone();
    |                              ^^^^^ method not found in `Bar<NotClone>`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<Bar<NotClone>>` here
+   |        the method is available for `std::rc::Rc<Bar<NotClone>>` here
    |
    = note: the method `clone` exists but the following trait bounds were not satisfied:
            `NotClone: std::clone::Clone`
diff --git a/src/test/ui/error-codes/E0004-2.rs b/src/test/ui/error-codes/E0004-2.rs
index c7612fd50a74e..7f1d064cf3f50 100644
--- a/src/test/ui/error-codes/E0004-2.rs
+++ b/src/test/ui/error-codes/E0004-2.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 fn main() {
     let x = Some(1);
 
diff --git a/src/test/ui/error-codes/E0004-2.stderr b/src/test/ui/error-codes/E0004-2.stderr
index f5b41cd1cc0bb..e47a4fa755cac 100644
--- a/src/test/ui/error-codes/E0004-2.stderr
+++ b/src/test/ui/error-codes/E0004-2.stderr
@@ -1,8 +1,16 @@
 error[E0004]: non-exhaustive patterns: `None` and `Some(_)` not covered
-  --> $DIR/E0004-2.rs:4:11
+  --> $DIR/E0004-2.rs:9:11
    |
 LL |     match x { }
    |           ^ patterns `None` and `Some(_)` not covered
+   | 
+  ::: $SRC_DIR/libcore/option.rs:LL:COL
+   |
+LL |     None,
+   |     ---- not covered
+...
+LL |     Some(#[stable(feature = "rust1", since = "1.0.0")] T),
+   |     ---- not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
diff --git a/src/test/ui/error-codes/E0005.rs b/src/test/ui/error-codes/E0005.rs
index f4730697e1843..75faad80579c6 100644
--- a/src/test/ui/error-codes/E0005.rs
+++ b/src/test/ui/error-codes/E0005.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 fn main() {
     let x = Some(1);
     let Some(y) = x; //~ ERROR E0005
diff --git a/src/test/ui/error-codes/E0005.stderr b/src/test/ui/error-codes/E0005.stderr
index 577c6e886d523..192b994403191 100644
--- a/src/test/ui/error-codes/E0005.stderr
+++ b/src/test/ui/error-codes/E0005.stderr
@@ -1,8 +1,13 @@
 error[E0005]: refutable pattern in local binding: `None` not covered
-  --> $DIR/E0005.rs:3:9
+  --> $DIR/E0005.rs:8:9
    |
 LL |     let Some(y) = x;
    |         ^^^^^^^ pattern `None` not covered
+   | 
+  ::: $SRC_DIR/libcore/option.rs:LL:COL
+   |
+LL |     None,
+   |     ---- not covered
    |
    = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
    = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
diff --git a/src/test/ui/error-codes/E0297.rs b/src/test/ui/error-codes/E0297.rs
index 27c7960d97731..b26ede9c8e219 100644
--- a/src/test/ui/error-codes/E0297.rs
+++ b/src/test/ui/error-codes/E0297.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 fn main() {
     let xs : Vec<Option<i32>> = vec![Some(1), None];
 
diff --git a/src/test/ui/error-codes/E0297.stderr b/src/test/ui/error-codes/E0297.stderr
index f356a5b954d6d..4a75e9d1771f3 100644
--- a/src/test/ui/error-codes/E0297.stderr
+++ b/src/test/ui/error-codes/E0297.stderr
@@ -1,8 +1,13 @@
 error[E0005]: refutable pattern in `for` loop binding: `None` not covered
-  --> $DIR/E0297.rs:4:9
+  --> $DIR/E0297.rs:9:9
    |
 LL |     for Some(x) in xs {}
    |         ^^^^^^^ pattern `None` not covered
+   | 
+  ::: $SRC_DIR/libcore/option.rs:LL:COL
+   |
+LL |     None,
+   |     ---- not covered
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.rs b/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.rs
index f0cc9ea70550e..d2e52299c0d86 100644
--- a/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.rs
+++ b/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 #![feature(never_type)]
 
 fn foo() -> Result<u32, !> {
diff --git a/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.stderr b/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.stderr
index 08c36cece4cf9..c2dd90b91e700 100644
--- a/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.stderr
+++ b/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.stderr
@@ -1,8 +1,13 @@
 error[E0005]: refutable pattern in local binding: `Err(_)` not covered
-  --> $DIR/feature-gate-exhaustive-patterns.rs:8:9
+  --> $DIR/feature-gate-exhaustive-patterns.rs:13:9
    |
 LL |     let Ok(_x) = foo();
    |         ^^^^^^ pattern `Err(_)` not covered
+   | 
+  ::: $SRC_DIR/libcore/result.rs:LL:COL
+   |
+LL |     Err(#[stable(feature = "rust1", since = "1.0.0")] E),
+   |     --- not covered
    |
    = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
    = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
diff --git a/src/test/ui/generator/borrowing.stderr b/src/test/ui/generator/borrowing.stderr
index 83987e19839ce..38e1ace8c4efb 100644
--- a/src/test/ui/generator/borrowing.stderr
+++ b/src/test/ui/generator/borrowing.stderr
@@ -1,19 +1,16 @@
 error[E0597]: `a` does not live long enough
   --> $DIR/borrowing.rs:9:33
    |
+LL |     let _b = {
+   |         -- borrow later stored here
+LL |         let a = 3;
 LL |         Pin::new(&mut || yield &a).resume(())
-   |                       ----------^
-   |                       |         |
-   |                       |         borrowed value does not live long enough
+   |                       --        ^ borrowed value does not live long enough
+   |                       |
    |                       value captured here by generator
-   |                       a temporary with access to the borrow is created here ...
 LL |
 LL |     };
-   |     -- ... and the borrow might be used here, when that temporary is dropped and runs the destructor for generator
-   |     |
-   |     `a` dropped here while still borrowed
-   |
-   = note: The temporary is part of an expression at the end of a block. Consider forcing this temporary to be dropped sooner, before the block's local variables are dropped. For example, you could save the expression's value in a new local variable `x` and then make `x` be the expression at the end of the block.
+   |     - `a` dropped here while still borrowed
 
 error[E0597]: `a` does not live long enough
   --> $DIR/borrowing.rs:16:20
diff --git a/src/test/ui/generator/retain-resume-ref.stderr b/src/test/ui/generator/retain-resume-ref.stderr
index bc715c7030eb3..e33310d12d9ef 100644
--- a/src/test/ui/generator/retain-resume-ref.stderr
+++ b/src/test/ui/generator/retain-resume-ref.stderr
@@ -4,10 +4,9 @@ error[E0499]: cannot borrow `thing` as mutable more than once at a time
 LL |     gen.as_mut().resume(&mut thing);
    |                         ---------- first mutable borrow occurs here
 LL |     gen.as_mut().resume(&mut thing);
-   |                         ^^^^^^^^^^ second mutable borrow occurs here
-LL |
-LL | }
-   | - first borrow might be used here, when `gen` is dropped and runs the destructor for generator
+   |                  ------ ^^^^^^^^^^ second mutable borrow occurs here
+   |                  |
+   |                  first borrow later used by call
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/generic-associated-types/iterable.rs b/src/test/ui/generic-associated-types/iterable.rs
index 105ab4a8adc38..616421112db67 100644
--- a/src/test/ui/generic-associated-types/iterable.rs
+++ b/src/test/ui/generic-associated-types/iterable.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 #![allow(incomplete_features)]
 #![feature(generic_associated_types)]
 
diff --git a/src/test/ui/generic-associated-types/iterable.stderr b/src/test/ui/generic-associated-types/iterable.stderr
index ccb1c9bcc7f4e..e18c6cec64e71 100644
--- a/src/test/ui/generic-associated-types/iterable.stderr
+++ b/src/test/ui/generic-associated-types/iterable.stderr
@@ -1,10 +1,15 @@
 error[E0271]: type mismatch resolving `for<'a> <<std::vec::Vec<T> as Iterable>::Iter<'a> as std::iter::Iterator>::Item == <std::vec::Vec<T> as Iterable>::Item<'a>`
-  --> $DIR/iterable.rs:15:5
+  --> $DIR/iterable.rs:20:5
    |
 LL | impl<T> Iterable for Vec<T> {
    | --------------------------- in this `impl` item
 LL |     type Item<'a> where T: 'a = <std::slice::Iter<'a, T> as Iterator>::Item;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected reference, found associated type
+   | 
+  ::: $SRC_DIR/libcore/iter/traits/iterator.rs:LL:COL
+   |
+LL |     type Item;
+   |          ---- associated type defined here
    |
    = note:    expected reference `&T`
            found associated type `<std::vec::Vec<T> as Iterable>::Item<'_>`
@@ -12,12 +17,17 @@ LL |     type Item<'a> where T: 'a = <std::slice::Iter<'a, T> as Iterator>::Item
    = note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
 
 error[E0271]: type mismatch resolving `for<'a> <<[T] as Iterable>::Iter<'a> as std::iter::Iterator>::Item == <[T] as Iterable>::Item<'a>`
-  --> $DIR/iterable.rs:27:5
+  --> $DIR/iterable.rs:32:5
    |
 LL | impl<T> Iterable for [T] {
    | ------------------------ in this `impl` item
 LL |     type Item<'a> where T: 'a = <std::slice::Iter<'a, T> as Iterator>::Item;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected reference, found associated type
+   | 
+  ::: $SRC_DIR/libcore/iter/traits/iterator.rs:LL:COL
+   |
+LL |     type Item;
+   |          ---- associated type defined here
    |
    = note:    expected reference `&T`
            found associated type `<[T] as Iterable>::Item<'_>`
@@ -25,7 +35,7 @@ LL |     type Item<'a> where T: 'a = <std::slice::Iter<'a, T> as Iterator>::Item
    = note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
 
 error[E0271]: type mismatch resolving `for<'a> <<std::vec::Vec<T> as Iterable>::Iter<'a> as std::iter::Iterator>::Item == <std::vec::Vec<T> as Iterable>::Item<'a>`
-  --> $DIR/iterable.rs:19:30
+  --> $DIR/iterable.rs:24:30
    |
 LL | trait Iterable {
    | -------------- required by `Iterable`
@@ -39,7 +49,7 @@ LL |     fn iter<'a>(&'a self) -> Self::Iter<'a> {
    = note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
 
 error[E0271]: type mismatch resolving `for<'a> <<[T] as Iterable>::Iter<'a> as std::iter::Iterator>::Item == <[T] as Iterable>::Item<'a>`
-  --> $DIR/iterable.rs:31:30
+  --> $DIR/iterable.rs:36:30
    |
 LL | trait Iterable {
    | -------------- required by `Iterable`
diff --git a/src/test/ui/impl-trait/no-method-suggested-traits.stderr b/src/test/ui/impl-trait/no-method-suggested-traits.stderr
index c0ca341385df5..b5135b53e1890 100644
--- a/src/test/ui/impl-trait/no-method-suggested-traits.stderr
+++ b/src/test/ui/impl-trait/no-method-suggested-traits.stderr
@@ -83,6 +83,16 @@ error[E0599]: no method named `method` found for struct `std::rc::Rc<&mut std::b
    |
 LL |     std::rc::Rc::new(&mut Box::new(&1i32)).method();
    |                                            ^^^^^^ method not found in `std::rc::Rc<&mut std::boxed::Box<&i32>>`
+   | 
+  ::: $DIR/auxiliary/no_method_suggested_traits.rs:8:12
+   |
+LL |         fn method(&self) {}
+   |            ------
+   |            |
+   |            the method is available for `std::boxed::Box<std::rc::Rc<&mut std::boxed::Box<&i32>>>` here
+   |            the method is available for `std::pin::Pin<std::rc::Rc<&mut std::boxed::Box<&i32>>>` here
+   |            the method is available for `std::sync::Arc<std::rc::Rc<&mut std::boxed::Box<&i32>>>` here
+   |            the method is available for `std::rc::Rc<std::rc::Rc<&mut std::boxed::Box<&i32>>>` here
    |
    = help: items from traits can only be used if the trait is in scope
 help: the following trait is implemented but not in scope; perhaps add a `use` for it:
diff --git a/src/test/ui/issues/issue-2823.rs b/src/test/ui/issues/issue-2823.rs
index 7b443b4152613..f00c2304733ca 100644
--- a/src/test/ui/issues/issue-2823.rs
+++ b/src/test/ui/issues/issue-2823.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 struct C {
     x: isize,
 }
diff --git a/src/test/ui/issues/issue-2823.stderr b/src/test/ui/issues/issue-2823.stderr
index aa720fd45895a..6e11dd4028836 100644
--- a/src/test/ui/issues/issue-2823.stderr
+++ b/src/test/ui/issues/issue-2823.stderr
@@ -1,11 +1,19 @@
 error[E0599]: no method named `clone` found for struct `C` in the current scope
-  --> $DIR/issue-2823.rs:13:16
+  --> $DIR/issue-2823.rs:18:16
    |
 LL | struct C {
    | -------- method `clone` not found for this
 ...
 LL |     let _d = c.clone();
    |                ^^^^^ method not found in `C`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<C>` here
+   |        the method is available for `std::rc::Rc<C>` here
    |
    = help: items from traits can only be used if the trait is implemented and in scope
    = note: the following trait defines an item `clone`, perhaps you need to implement it:
diff --git a/src/test/ui/issues/issue-69725.rs b/src/test/ui/issues/issue-69725.rs
index b8130b41f2167..a8e72e9459e33 100644
--- a/src/test/ui/issues/issue-69725.rs
+++ b/src/test/ui/issues/issue-69725.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 // aux-build:issue-69725.rs
 
 extern crate issue_69725;
diff --git a/src/test/ui/issues/issue-69725.stderr b/src/test/ui/issues/issue-69725.stderr
index 667383e072a54..439fae9511167 100644
--- a/src/test/ui/issues/issue-69725.stderr
+++ b/src/test/ui/issues/issue-69725.stderr
@@ -1,5 +1,5 @@
 error[E0599]: no method named `clone` found for struct `issue_69725::Struct<A>` in the current scope
-  --> $DIR/issue-69725.rs:7:32
+  --> $DIR/issue-69725.rs:12:32
    |
 LL |     let _ = Struct::<A>::new().clone();
    |                                ^^^^^ method not found in `issue_69725::Struct<A>`
@@ -8,6 +8,14 @@ LL |     let _ = Struct::<A>::new().clone();
    |
 LL | pub struct Struct<A>(A);
    | ------------------------ doesn't satisfy `issue_69725::Struct<A>: std::clone::Clone`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<issue_69725::Struct<A>>` here
+   |        the method is available for `std::rc::Rc<issue_69725::Struct<A>>` here
    |
    = note: the method `clone` exists but the following trait bounds were not satisfied:
            `A: std::clone::Clone`
diff --git a/src/test/ui/non-copyable-void.rs b/src/test/ui/non-copyable-void.rs
index ddaaee436ae23..186731f2e7233 100644
--- a/src/test/ui/non-copyable-void.rs
+++ b/src/test/ui/non-copyable-void.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 // ignore-wasm32-bare no libc to test ffi with
 
 #![feature(rustc_private)]
diff --git a/src/test/ui/non-copyable-void.stderr b/src/test/ui/non-copyable-void.stderr
index 074ed66a26183..dd67a110d2218 100644
--- a/src/test/ui/non-copyable-void.stderr
+++ b/src/test/ui/non-copyable-void.stderr
@@ -1,8 +1,16 @@
 error[E0599]: no method named `clone` found for enum `libc::c_void` in the current scope
-  --> $DIR/non-copyable-void.rs:11:23
+  --> $DIR/non-copyable-void.rs:16:23
    |
 LL |         let _z = (*y).clone();
    |                       ^^^^^ method not found in `libc::c_void`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<libc::c_void>` here
+   |        the method is available for `std::rc::Rc<libc::c_void>` here
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/noncopyable-class.rs b/src/test/ui/noncopyable-class.rs
index 11b6eb736e9db..731f4ab9c784a 100644
--- a/src/test/ui/noncopyable-class.rs
+++ b/src/test/ui/noncopyable-class.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 // Test that a class with a non-copyable field can't be
 // copied
 
diff --git a/src/test/ui/noncopyable-class.stderr b/src/test/ui/noncopyable-class.stderr
index 6c3c4a6ac9888..472ce34870a0a 100644
--- a/src/test/ui/noncopyable-class.stderr
+++ b/src/test/ui/noncopyable-class.stderr
@@ -1,11 +1,19 @@
 error[E0599]: no method named `clone` found for struct `Foo` in the current scope
-  --> $DIR/noncopyable-class.rs:34:16
+  --> $DIR/noncopyable-class.rs:39:16
    |
 LL | struct Foo {
    | ---------- method `clone` not found for this
 ...
 LL |     let _y = x.clone();
    |                ^^^^^ method not found in `Foo`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<Foo>` here
+   |        the method is available for `std::rc::Rc<Foo>` here
    |
    = help: items from traits can only be used if the trait is implemented and in scope
    = note: the following trait defines an item `clone`, perhaps you need to implement it:
diff --git a/src/test/ui/pattern/usefulness/match-arm-statics-2.rs b/src/test/ui/pattern/usefulness/match-arm-statics-2.rs
index 4c5f2d356491b..728d4a64495b1 100644
--- a/src/test/ui/pattern/usefulness/match-arm-statics-2.rs
+++ b/src/test/ui/pattern/usefulness/match-arm-statics-2.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 use self::Direction::{North, East, South, West};
 
 #[derive(PartialEq, Eq)]
diff --git a/src/test/ui/pattern/usefulness/match-arm-statics-2.stderr b/src/test/ui/pattern/usefulness/match-arm-statics-2.stderr
index 8521e37d3fddc..7bb6a700a3717 100644
--- a/src/test/ui/pattern/usefulness/match-arm-statics-2.stderr
+++ b/src/test/ui/pattern/usefulness/match-arm-statics-2.stderr
@@ -1,5 +1,5 @@
 error[E0004]: non-exhaustive patterns: `(true, false)` not covered
-  --> $DIR/match-arm-statics-2.rs:17:11
+  --> $DIR/match-arm-statics-2.rs:22:11
    |
 LL |     match (true, false) {
    |           ^^^^^^^^^^^^^ pattern `(true, false)` not covered
@@ -7,15 +7,23 @@ LL |     match (true, false) {
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: `Some(Some(West))` not covered
-  --> $DIR/match-arm-statics-2.rs:29:11
+  --> $DIR/match-arm-statics-2.rs:34:11
    |
 LL |     match Some(Some(North)) {
    |           ^^^^^^^^^^^^^^^^^ pattern `Some(Some(West))` not covered
+   | 
+  ::: $SRC_DIR/libcore/option.rs:LL:COL
+   |
+LL |     Some(#[stable(feature = "rust1", since = "1.0.0")] T),
+   |     ----
+   |     |
+   |     not covered
+   |     not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: `Foo { bar: Some(North), baz: NewBool(true) }` not covered
-  --> $DIR/match-arm-statics-2.rs:48:11
+  --> $DIR/match-arm-statics-2.rs:53:11
    |
 LL | / struct Foo {
 LL | |     bar: Option<Direction>,
diff --git a/src/test/ui/pattern/usefulness/match-privately-empty.rs b/src/test/ui/pattern/usefulness/match-privately-empty.rs
index 315eb03d16564..c7cde468bb9bf 100644
--- a/src/test/ui/pattern/usefulness/match-privately-empty.rs
+++ b/src/test/ui/pattern/usefulness/match-privately-empty.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 #![feature(never_type)]
 #![feature(exhaustive_patterns)]
 
diff --git a/src/test/ui/pattern/usefulness/match-privately-empty.stderr b/src/test/ui/pattern/usefulness/match-privately-empty.stderr
index f79d180a1b8b5..4dcbf05ecce2b 100644
--- a/src/test/ui/pattern/usefulness/match-privately-empty.stderr
+++ b/src/test/ui/pattern/usefulness/match-privately-empty.stderr
@@ -1,8 +1,13 @@
 error[E0004]: non-exhaustive patterns: `Some(Private { misc: true, .. })` not covered
-  --> $DIR/match-privately-empty.rs:13:11
+  --> $DIR/match-privately-empty.rs:18:11
    |
 LL |     match private::DATA {
    |           ^^^^^^^^^^^^^ pattern `Some(Private { misc: true, .. })` not covered
+   | 
+  ::: $SRC_DIR/libcore/option.rs:LL:COL
+   |
+LL |     Some(#[stable(feature = "rust1", since = "1.0.0")] T),
+   |     ---- not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
diff --git a/src/test/ui/pattern/usefulness/non-exhaustive-match.rs b/src/test/ui/pattern/usefulness/non-exhaustive-match.rs
index 9947989dc1211..59f7bb892c68c 100644
--- a/src/test/ui/pattern/usefulness/non-exhaustive-match.rs
+++ b/src/test/ui/pattern/usefulness/non-exhaustive-match.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 #![allow(illegal_floating_point_literal_pattern)]
 
 enum T { A, B }
diff --git a/src/test/ui/pattern/usefulness/non-exhaustive-match.stderr b/src/test/ui/pattern/usefulness/non-exhaustive-match.stderr
index a06ad5788515c..dff2c8d9424c3 100644
--- a/src/test/ui/pattern/usefulness/non-exhaustive-match.stderr
+++ b/src/test/ui/pattern/usefulness/non-exhaustive-match.stderr
@@ -1,5 +1,5 @@
 error[E0004]: non-exhaustive patterns: `A` not covered
-  --> $DIR/non-exhaustive-match.rs:7:11
+  --> $DIR/non-exhaustive-match.rs:12:11
    |
 LL | enum T { A, B }
    | ---------------
@@ -13,7 +13,7 @@ LL |     match x { T::B => { } }
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: `false` not covered
-  --> $DIR/non-exhaustive-match.rs:8:11
+  --> $DIR/non-exhaustive-match.rs:13:11
    |
 LL |     match true {
    |           ^^^^ pattern `false` not covered
@@ -21,15 +21,20 @@ LL |     match true {
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: `Some(_)` not covered
-  --> $DIR/non-exhaustive-match.rs:11:11
+  --> $DIR/non-exhaustive-match.rs:16:11
    |
 LL |     match Some(10) {
    |           ^^^^^^^^ pattern `Some(_)` not covered
+   | 
+  ::: $SRC_DIR/libcore/option.rs:LL:COL
+   |
+LL |     Some(#[stable(feature = "rust1", since = "1.0.0")] T),
+   |     ---- not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: `(_, _, std::i32::MIN..=3i32)` and `(_, _, 5i32..=std::i32::MAX)` not covered
-  --> $DIR/non-exhaustive-match.rs:14:11
+  --> $DIR/non-exhaustive-match.rs:19:11
    |
 LL |     match (2, 3, 4) {
    |           ^^^^^^^^^ patterns `(_, _, std::i32::MIN..=3i32)` and `(_, _, 5i32..=std::i32::MAX)` not covered
@@ -37,7 +42,7 @@ LL |     match (2, 3, 4) {
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: `(A, A)` not covered
-  --> $DIR/non-exhaustive-match.rs:18:11
+  --> $DIR/non-exhaustive-match.rs:23:11
    |
 LL |     match (T::A, T::A) {
    |           ^^^^^^^^^^^^ pattern `(A, A)` not covered
@@ -45,7 +50,7 @@ LL |     match (T::A, T::A) {
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: `B` not covered
-  --> $DIR/non-exhaustive-match.rs:22:11
+  --> $DIR/non-exhaustive-match.rs:27:11
    |
 LL | enum T { A, B }
    | ---------------
@@ -59,7 +64,7 @@ LL |     match T::A {
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: `[]` not covered
-  --> $DIR/non-exhaustive-match.rs:33:11
+  --> $DIR/non-exhaustive-match.rs:38:11
    |
 LL |     match *vec {
    |           ^^^^ pattern `[]` not covered
@@ -67,7 +72,7 @@ LL |     match *vec {
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: `[_, _, _, _, ..]` not covered
-  --> $DIR/non-exhaustive-match.rs:46:11
+  --> $DIR/non-exhaustive-match.rs:51:11
    |
 LL |     match *vec {
    |           ^^^^ pattern `[_, _, _, _, ..]` not covered
diff --git a/src/test/ui/recursion/recursive-types-are-not-uninhabited.rs b/src/test/ui/recursion/recursive-types-are-not-uninhabited.rs
index 4489303638358..5be426eb38278 100644
--- a/src/test/ui/recursion/recursive-types-are-not-uninhabited.rs
+++ b/src/test/ui/recursion/recursive-types-are-not-uninhabited.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 struct R<'a> {
     r: &'a R<'a>,
 }
diff --git a/src/test/ui/recursion/recursive-types-are-not-uninhabited.stderr b/src/test/ui/recursion/recursive-types-are-not-uninhabited.stderr
index aa23aed4b425a..f371d460cf733 100644
--- a/src/test/ui/recursion/recursive-types-are-not-uninhabited.stderr
+++ b/src/test/ui/recursion/recursive-types-are-not-uninhabited.stderr
@@ -1,8 +1,13 @@
 error[E0005]: refutable pattern in local binding: `Err(_)` not covered
-  --> $DIR/recursive-types-are-not-uninhabited.rs:6:9
+  --> $DIR/recursive-types-are-not-uninhabited.rs:11:9
    |
 LL |     let Ok(x) = res;
    |         ^^^^^ pattern `Err(_)` not covered
+   | 
+  ::: $SRC_DIR/libcore/result.rs:LL:COL
+   |
+LL |     Err(#[stable(feature = "rust1", since = "1.0.0")] E),
+   |     --- not covered
    |
    = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
    = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
diff --git a/src/test/ui/resolve/issue-3907-2.stderr b/src/test/ui/resolve/issue-3907-2.stderr
index d0c278d12d70a..bd6e9d5950272 100644
--- a/src/test/ui/resolve/issue-3907-2.stderr
+++ b/src/test/ui/resolve/issue-3907-2.stderr
@@ -3,8 +3,11 @@ error[E0038]: the trait `issue_3907::Foo` cannot be made into an object
    |
 LL | fn bar(_x: Foo) {}
    |            ^^^ the trait `issue_3907::Foo` cannot be made into an object
+   | 
+  ::: $DIR/auxiliary/issue-3907.rs:2:8
    |
-   = note: the trait cannot be made into an object because associated function `bar` has no `self` parameter
+LL |     fn bar();
+   |        --- the trait cannot be made into an object because associated function `bar` has no `self` parameter
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match.stderr b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match.stderr
index ccc25a184e946..a214a652a387f 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match.stderr
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match.stderr
@@ -27,6 +27,13 @@ error[E0004]: non-exhaustive patterns: `Tuple(_)` and `Struct { .. }` not covere
    |
 LL |     match x {}
    |           ^ patterns `Tuple(_)` and `Struct { .. }` not covered
+   | 
+  ::: $DIR/auxiliary/uninhabited.rs:17:23
+   |
+LL |     #[non_exhaustive] Tuple(!),
+   |                       ----- not covered
+LL |     #[non_exhaustive] Struct { x: ! }
+   |                       ------ not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
diff --git a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns.stderr b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns.stderr
index a54885c96e5ee..63564e9c3cc8c 100644
--- a/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns.stderr
+++ b/src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns.stderr
@@ -27,6 +27,13 @@ error[E0004]: non-exhaustive patterns: `Tuple(_)` and `Struct { .. }` not covere
    |
 LL |     match x {}
    |           ^ patterns `Tuple(_)` and `Struct { .. }` not covered
+   | 
+  ::: $DIR/auxiliary/uninhabited.rs:17:23
+   |
+LL |     #[non_exhaustive] Tuple(!),
+   |                       ----- not covered
+LL |     #[non_exhaustive] Struct { x: ! }
+   |                       ------ not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
diff --git a/src/test/ui/self/elision/ref-self-async.nll.stderr b/src/test/ui/self/elision/ref-self-async.nll.stderr
index 541e49543221e..bd1f80811b542 100644
--- a/src/test/ui/self/elision/ref-self-async.nll.stderr
+++ b/src/test/ui/self/elision/ref-self-async.nll.stderr
@@ -1,13 +1,72 @@
-error[E0658]: `Wrap<&Struct, Struct>` cannot be used as the type of `self` without the `arbitrary_self_types` feature
-  --> $DIR/ref-self-async.rs:47:39
+error: lifetime may not live long enough
+  --> $DIR/ref-self-async.rs:23:9
    |
-LL |     async fn wrap_ref_Self_Self(self: Wrap<&Self, Self>, f: &u8) -> &u8 {
-   |                                       ^^^^^^^^^^^^^^^^^
+LL |     async fn ref_self(&self, f: &u32) -> &u32 {
+   |                       -         - let's call the lifetime of this reference `'1`
+   |                       |
+   |                       let's call the lifetime of this reference `'2`
+LL |         f
+   |         ^ associated function was supposed to return data with lifetime `'2` but it is returning data with lifetime `'1`
+
+error: lifetime may not live long enough
+  --> $DIR/ref-self-async.rs:29:9
+   |
+LL |     async fn ref_Self(self: &Self, f: &u32) -> &u32 {
+   |                             -         - let's call the lifetime of this reference `'1`
+   |                             |
+   |                             let's call the lifetime of this reference `'2`
+LL |         f
+   |         ^ associated function was supposed to return data with lifetime `'2` but it is returning data with lifetime `'1`
+
+error: lifetime may not live long enough
+  --> $DIR/ref-self-async.rs:33:9
    |
-   = note: see issue #44874 <https://github.com/rust-lang/rust/issues/44874> for more information
-   = help: add `#![feature(arbitrary_self_types)]` to the crate attributes to enable
-   = help: consider changing to `self`, `&self`, `&mut self`, `self: Box<Self>`, `self: Rc<Self>`, `self: Arc<Self>`, or `self: Pin<P>` (where P is one of the previous types except `Self`)
+LL |     async fn box_ref_Self(self: Box<&Self>, f: &u32) -> &u32 {
+   |                                     -          - let's call the lifetime of this reference `'1`
+   |                                     |
+   |                                     let's call the lifetime of this reference `'2`
+LL |         f
+   |         ^ associated function was supposed to return data with lifetime `'2` but it is returning data with lifetime `'1`
+
+error: lifetime may not live long enough
+  --> $DIR/ref-self-async.rs:37:9
+   |
+LL |     async fn pin_ref_Self(self: Pin<&Self>, f: &u32) -> &u32 {
+   |                                     -          - let's call the lifetime of this reference `'1`
+   |                                     |
+   |                                     let's call the lifetime of this reference `'2`
+LL |         f
+   |         ^ associated function was supposed to return data with lifetime `'2` but it is returning data with lifetime `'1`
+
+error: lifetime may not live long enough
+  --> $DIR/ref-self-async.rs:41:9
+   |
+LL |     async fn box_box_ref_Self(self: Box<Box<&Self>>, f: &u32) -> &u32 {
+   |                                             -           - let's call the lifetime of this reference `'1`
+   |                                             |
+   |                                             let's call the lifetime of this reference `'2`
+LL |         f
+   |         ^ associated function was supposed to return data with lifetime `'2` but it is returning data with lifetime `'1`
+
+error: lifetime may not live long enough
+  --> $DIR/ref-self-async.rs:45:9
+   |
+LL |     async fn box_pin_ref_Self(self: Box<Pin<&Self>>, f: &u32) -> &u32 {
+   |                                             -           - let's call the lifetime of this reference `'1`
+   |                                             |
+   |                                             let's call the lifetime of this reference `'2`
+LL |         f
+   |         ^ associated function was supposed to return data with lifetime `'2` but it is returning data with lifetime `'1`
+
+error: lifetime may not live long enough
+  --> $DIR/ref-self-async.rs:49:9
+   |
+LL |     async fn wrap_ref_Self_Self(self: Wrap<&Self, Self>, f: &u8) -> &u8 {
+   |                                            -                - let's call the lifetime of this reference `'1`
+   |                                            |
+   |                                            let's call the lifetime of this reference `'2`
+LL |         f
+   |         ^ associated function was supposed to return data with lifetime `'2` but it is returning data with lifetime `'1`
 
-error: aborting due to previous error
+error: aborting due to 7 previous errors
 
-For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/self/elision/ref-self-async.rs b/src/test/ui/self/elision/ref-self-async.rs
index 6a98b79cb3bba..0fbbd95c975d6 100644
--- a/src/test/ui/self/elision/ref-self-async.rs
+++ b/src/test/ui/self/elision/ref-self-async.rs
@@ -1,6 +1,7 @@
 // edition:2018
 
 #![allow(non_snake_case)]
+#![feature(arbitrary_self_types)]
 
 use std::marker::PhantomData;
 use std::ops::Deref;
diff --git a/src/test/ui/self/elision/ref-self-async.stderr b/src/test/ui/self/elision/ref-self-async.stderr
index b73290b024f8f..bda958241b67b 100644
--- a/src/test/ui/self/elision/ref-self-async.stderr
+++ b/src/test/ui/self/elision/ref-self-async.stderr
@@ -1,5 +1,5 @@
 error[E0623]: lifetime mismatch
-  --> $DIR/ref-self-async.rs:22:9
+  --> $DIR/ref-self-async.rs:23:9
    |
 LL |     async fn ref_self(&self, f: &u32) -> &u32 {
    |                       -----              ----
@@ -9,7 +9,7 @@ LL |         f
    |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
-  --> $DIR/ref-self-async.rs:28:9
+  --> $DIR/ref-self-async.rs:29:9
    |
 LL |     async fn ref_Self(self: &Self, f: &u32) -> &u32 {
    |                             -----              ----
@@ -19,7 +19,7 @@ LL |         f
    |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
-  --> $DIR/ref-self-async.rs:32:9
+  --> $DIR/ref-self-async.rs:33:9
    |
 LL |     async fn box_ref_Self(self: Box<&Self>, f: &u32) -> &u32 {
    |                                     -----               ----
@@ -29,7 +29,7 @@ LL |         f
    |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
-  --> $DIR/ref-self-async.rs:36:9
+  --> $DIR/ref-self-async.rs:37:9
    |
 LL |     async fn pin_ref_Self(self: Pin<&Self>, f: &u32) -> &u32 {
    |                                     -----               ----
@@ -39,7 +39,7 @@ LL |         f
    |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
-  --> $DIR/ref-self-async.rs:40:9
+  --> $DIR/ref-self-async.rs:41:9
    |
 LL |     async fn box_box_ref_Self(self: Box<Box<&Self>>, f: &u32) -> &u32 {
    |                                             -----                ----
@@ -49,7 +49,7 @@ LL |         f
    |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
-  --> $DIR/ref-self-async.rs:44:9
+  --> $DIR/ref-self-async.rs:45:9
    |
 LL |     async fn box_pin_ref_Self(self: Box<Pin<&Self>>, f: &u32) -> &u32 {
    |                                             -----                ----
@@ -59,7 +59,7 @@ LL |         f
    |         ^ ...but data from `f` is returned here
 
 error[E0623]: lifetime mismatch
-  --> $DIR/ref-self-async.rs:48:9
+  --> $DIR/ref-self-async.rs:49:9
    |
 LL |     async fn wrap_ref_Self_Self(self: Wrap<&Self, Self>, f: &u8) -> &u8 {
    |                                            -----                    ---
diff --git a/src/test/ui/uninhabited/uninhabited-matches-feature-gated.rs b/src/test/ui/uninhabited/uninhabited-matches-feature-gated.rs
index e804afcf9ed99..a959aaae05568 100644
--- a/src/test/ui/uninhabited/uninhabited-matches-feature-gated.rs
+++ b/src/test/ui/uninhabited/uninhabited-matches-feature-gated.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 use std::mem::zeroed;
 enum Void {}
 
diff --git a/src/test/ui/uninhabited/uninhabited-matches-feature-gated.stderr b/src/test/ui/uninhabited/uninhabited-matches-feature-gated.stderr
index a667e1fe2da3a..9245e293caa85 100644
--- a/src/test/ui/uninhabited/uninhabited-matches-feature-gated.stderr
+++ b/src/test/ui/uninhabited/uninhabited-matches-feature-gated.stderr
@@ -1,13 +1,18 @@
 error[E0004]: non-exhaustive patterns: `Err(_)` not covered
-  --> $DIR/uninhabited-matches-feature-gated.rs:6:19
+  --> $DIR/uninhabited-matches-feature-gated.rs:11:19
    |
 LL |     let _ = match x {
    |                   ^ pattern `Err(_)` not covered
+   | 
+  ::: $SRC_DIR/libcore/result.rs:LL:COL
+   |
+LL |     Err(#[stable(feature = "rust1", since = "1.0.0")] E),
+   |     --- not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: type `&Void` is non-empty
-  --> $DIR/uninhabited-matches-feature-gated.rs:15:19
+  --> $DIR/uninhabited-matches-feature-gated.rs:20:19
    |
 LL | enum Void {}
    | ------------ `Void` defined here
@@ -18,7 +23,7 @@ LL |     let _ = match x {};
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: type `(Void,)` is non-empty
-  --> $DIR/uninhabited-matches-feature-gated.rs:18:19
+  --> $DIR/uninhabited-matches-feature-gated.rs:23:19
    |
 LL |     let _ = match x {};
    |                   ^
@@ -26,7 +31,7 @@ LL |     let _ = match x {};
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: type `[Void; 1]` is non-empty
-  --> $DIR/uninhabited-matches-feature-gated.rs:21:19
+  --> $DIR/uninhabited-matches-feature-gated.rs:26:19
    |
 LL |     let _ = match x {};
    |                   ^
@@ -34,7 +39,7 @@ LL |     let _ = match x {};
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: `&[_, ..]` not covered
-  --> $DIR/uninhabited-matches-feature-gated.rs:24:19
+  --> $DIR/uninhabited-matches-feature-gated.rs:29:19
    |
 LL |     let _ = match x {
    |                   ^ pattern `&[_, ..]` not covered
@@ -42,18 +47,28 @@ LL |     let _ = match x {
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0004]: non-exhaustive patterns: `Err(_)` not covered
-  --> $DIR/uninhabited-matches-feature-gated.rs:32:19
+  --> $DIR/uninhabited-matches-feature-gated.rs:37:19
    |
 LL |     let _ = match x {
    |                   ^ pattern `Err(_)` not covered
+   | 
+  ::: $SRC_DIR/libcore/result.rs:LL:COL
+   |
+LL |     Err(#[stable(feature = "rust1", since = "1.0.0")] E),
+   |     --- not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
 error[E0005]: refutable pattern in local binding: `Err(_)` not covered
-  --> $DIR/uninhabited-matches-feature-gated.rs:37:9
+  --> $DIR/uninhabited-matches-feature-gated.rs:42:9
    |
 LL |     let Ok(x) = x;
    |         ^^^^^ pattern `Err(_)` not covered
+   | 
+  ::: $SRC_DIR/libcore/result.rs:LL:COL
+   |
+LL |     Err(#[stable(feature = "rust1", since = "1.0.0")] E),
+   |     --- not covered
    |
    = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
    = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
diff --git a/src/test/ui/union/union-derive-clone.rs b/src/test/ui/union/union-derive-clone.rs
index 4a106cc940a18..4b92475f1e4cd 100644
--- a/src/test/ui/union/union-derive-clone.rs
+++ b/src/test/ui/union/union-derive-clone.rs
@@ -1,3 +1,8 @@
+// FIXME: missing sysroot spans (#53081)
+// ignore-i586-unknown-linux-gnu
+// ignore-i586-unknown-linux-musl
+// ignore-i686-unknown-linux-musl
+
 #![feature(untagged_unions)]
 
 use std::mem::ManuallyDrop;
diff --git a/src/test/ui/union/union-derive-clone.stderr b/src/test/ui/union/union-derive-clone.stderr
index 01c8e8471aac2..d0a82a96c165c 100644
--- a/src/test/ui/union/union-derive-clone.stderr
+++ b/src/test/ui/union/union-derive-clone.stderr
@@ -1,5 +1,5 @@
 error[E0277]: the trait bound `U1: std::marker::Copy` is not satisfied
-  --> $DIR/union-derive-clone.rs:5:10
+  --> $DIR/union-derive-clone.rs:10:10
    |
 LL | #[derive(Clone)]
    |          ^^^^^ the trait `std::marker::Copy` is not implemented for `U1`
@@ -8,7 +8,7 @@ LL | #[derive(Clone)]
    = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0599]: no method named `clone` found for union `U5<CloneNoCopy>` in the current scope
-  --> $DIR/union-derive-clone.rs:37:15
+  --> $DIR/union-derive-clone.rs:42:15
    |
 LL | union U5<T> {
    | -----------
@@ -21,6 +21,14 @@ LL | struct CloneNoCopy;
 ...
 LL |     let w = u.clone();
    |               ^^^^^ method not found in `U5<CloneNoCopy>`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<U5<CloneNoCopy>>` here
+   |        the method is available for `std::rc::Rc<U5<CloneNoCopy>>` here
    |
    = note: the method `clone` exists but the following trait bounds were not satisfied:
            `CloneNoCopy: std::marker::Copy`
diff --git a/src/test/ui/unique-object-noncopyable.stderr b/src/test/ui/unique-object-noncopyable.stderr
index fb78095224b90..2e81e7cf83200 100644
--- a/src/test/ui/unique-object-noncopyable.stderr
+++ b/src/test/ui/unique-object-noncopyable.stderr
@@ -14,6 +14,14 @@ LL |     let _z = y.clone();
    |
 LL | pub struct Box<T: ?Sized>(Unique<T>);
    | ------------------------------------- doesn't satisfy `std::boxed::Box<dyn Foo>: std::clone::Clone`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<std::boxed::Box<dyn Foo>>` here
+   |        the method is available for `std::rc::Rc<std::boxed::Box<dyn Foo>>` here
    |
    = note: the method `clone` exists but the following trait bounds were not satisfied:
            `dyn Foo: std::marker::Sized`
diff --git a/src/test/ui/unique-pinned-nocopy.stderr b/src/test/ui/unique-pinned-nocopy.stderr
index ea6575d1d85dc..06c4b95baef56 100644
--- a/src/test/ui/unique-pinned-nocopy.stderr
+++ b/src/test/ui/unique-pinned-nocopy.stderr
@@ -11,6 +11,14 @@ LL |     let _j = i.clone();
    |
 LL | pub struct Box<T: ?Sized>(Unique<T>);
    | ------------------------------------- doesn't satisfy `std::boxed::Box<R>: std::clone::Clone`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<std::boxed::Box<R>>` here
+   |        the method is available for `std::rc::Rc<std::boxed::Box<R>>` here
    |
    = note: the method `clone` exists but the following trait bounds were not satisfied:
            `R: std::clone::Clone`