submodules: update clippy from 66df92a to c8e3cfb

Changes:
````
travis: temporarily disable rustfmt ci check until rust-lang#4742 is resolved
rustup rust-lang/rust#65792
Fix ICE rust-lang#4579
Add regression test for ICE rust-lang#4579
Run update_lints for Unicode lint
Re-add false positive check
Add raw string regression test for useless_format lint
Re-factor useless_format lint
Update Unicode lint tests
[Backported] Rustup to rust-lang/rust#59545
````

Fixes ##65888

.travis.yml

@@ -63,8 +63,9 @@ matrix:
       if: repo =~ /^rust-lang\/rust-clippy$/ AND branch IN (auto, try)
     - env: INTEGRATION=Geal/nom
       if: repo =~ /^rust-lang\/rust-clippy$/ AND branch IN (auto, try)
-    - env: INTEGRATION=rust-lang/rustfmt
-      if: repo =~ /^rust-lang\/rust-clippy$/ AND branch IN (auto, try)
+    # FIXME blocked on https://github.com/rust-lang/rust-clippy/issues/4742
+    #- env: INTEGRATION=rust-lang/rustfmt
+    #  if: repo =~ /^rust-lang\/rust-clippy$/ AND branch IN (auto, try)
     - env: INTEGRATION=hyperium/hyper
       if: repo =~ /^rust-lang\/rust-clippy$/ AND branch IN (auto, try)
     - env: INTEGRATION=bluss/rust-itertools

clippy_lints/src/lib.rs

@@ -37,8 +37,6 @@ extern crate rustc_typeck;
 #[allow(unused_extern_crates)]
 extern crate syntax;
 #[allow(unused_extern_crates)]
-extern crate syntax_expand;
-#[allow(unused_extern_crates)]
 extern crate syntax_pos;
 
 use rustc::lint::{self, LintId};

clippy_lints/src/misc.rs

@@ -596,7 +596,7 @@ fn is_used(cx: &LateContext<'_, '_>, expr: &Expr) -> bool {
 /// Tests whether an expression is in a macro expansion (e.g., something
 /// generated by `#[derive(...)]` or the like).
 fn in_attributes_expansion(expr: &Expr) -> bool {
-    use syntax_expand::hygiene::MacroKind;
+    use syntax_pos::hygiene::MacroKind;
     if expr.span.from_expansion() {
         let data = expr.span.ctxt().outer_expn_data();
 

clippy_lints/src/types.rs

@@ -19,8 +19,7 @@ use syntax::ast::{FloatTy, IntTy, LitIntType, LitKind, UintTy};
 use syntax::errors::DiagnosticBuilder;
 use syntax::source_map::Span;
 use syntax::symbol::{sym, Symbol};
-use syntax_expand::base::MacroKind;
-use syntax_expand::hygiene::ExpnKind;
+use syntax_pos::hygiene::{ExpnKind, MacroKind};
 
 use crate::consts::{constant, Constant};
 use crate::utils::paths;

clippy_lints/src/utils/mod.rs

@@ -45,7 +45,7 @@ use syntax::ast::{self, LitKind};
 use syntax::attr;
 use syntax::source_map::{Span, DUMMY_SP};
 use syntax::symbol::{kw, Symbol};
-use syntax_expand::hygiene::ExpnKind;
+use syntax_pos::hygiene::ExpnKind;
 
 use crate::consts::{constant, Constant};
 use crate::reexport::*;