Auto merge of #13001 - Veykril:scoped, r=Veykril

Replace crossbeam with std's scoped threads

Probably best to wait a week or two so we don't immediately give linux packagers problems again

crates/proc-macro-srv/Cargo.toml

@@ -24,7 +24,6 @@ tt = { path = "../tt", version = "0.0.0" }
 mbe = { path = "../mbe", version = "0.0.0" }
 paths = { path = "../paths", version = "0.0.0" }
 proc-macro-api = { path = "../proc-macro-api", version = "0.0.0" }
-crossbeam = "0.8.1"
 
 [dev-dependencies]
 expect-test = "1.4.0"

crates/proc-macro-srv/src/lib.rs

@@ -26,6 +26,7 @@ use std::{
     ffi::OsString,
     fs,
     path::{Path, PathBuf},
+    thread,
     time::SystemTime,
 };
 
@@ -65,18 +66,16 @@ impl ProcMacroSrv {
 
         let macro_body = task.macro_body.to_subtree();
         let attributes = task.attributes.map(|it| it.to_subtree());
-        // FIXME: replace this with std's scoped threads once they stabilize
-        // (then remove dependency on crossbeam)
-        let result = crossbeam::scope(|s| {
-            let res = match s
-                .builder()
+        let result = thread::scope(|s| {
+            let thread = thread::Builder::new()
                 .stack_size(EXPANDER_STACK_SIZE)
                 .name(task.macro_name.clone())
-                .spawn(|_| {
+                .spawn_scoped(s, || {
                     expander
                         .expand(&task.macro_name, &macro_body, attributes.as_ref())
                         .map(|it| FlatTree::new(&it))
-                }) {
+                });
+            let res = match thread {
                 Ok(handle) => handle.join(),
                 Err(e) => std::panic::resume_unwind(Box::new(e)),
             };
@@ -86,10 +85,6 @@ impl ProcMacroSrv {
                 Err(e) => std::panic::resume_unwind(e),
             }
         });
-        let result = match result {
-            Ok(result) => result,
-            Err(e) => std::panic::resume_unwind(e),
-        };
 
         prev_env.rollback();