Fix nits

Co-Authored-By: Mazdak Farrokhzad <twingoow@gmail.com>

Author: Aaron1011

src/librustc/ty/mod.rs

@@ -1690,7 +1690,7 @@ impl<'tcx> ParamEnv<'tcx> {
     /// which is the default.
     ///
     /// All opaque types in the caller_bounds of the `ParamEnv`
-    /// will be normalized to their underlying types
+    /// will be normalized to their underlying types.
     pub fn with_reveal_all_normalized(self, tcx: TyCtxt<'tcx>) -> Self {
         let caller_bounds = tcx.normalize_impl_trait_types(
             &self.caller_bounds

src/librustc/ty/util.rs

@@ -738,18 +738,18 @@ impl<'tcx> TyCtxt<'tcx> {
 }
 
 struct OpaqueTypeExpander<'tcx> {
-    // Contains the DefIds of the opaque types that are currently being
-    // expanded. When we expand an opaque type we insert the DefId of
+    // Contains the `DefId`s of the opaque types that are currently being
+    // expanded. When we expand an opaque type we insert the `DefId` of
     // that type, and when we finish expanding that type we remove the
-    // its DefId.
+    // its `DefId`.
     seen_opaque_tys: FxHashSet<DefId>,
     // Cache of all expansions we've seen so far. This is a critical
-    // optimization for some large types produced by async fn trees.
+    // optimization for some large types produced by `async fn` trees.
     expanded_cache: FxHashMap<(DefId, SubstsRef<'tcx>), Ty<'tcx>>,
     primary_def_id: Option<DefId>,
     found_recursion: bool,
     // Whether or not to check for recursive opaque types.
-    // This is 'true' when we're explicitly checking for opaque type
+    // This is `true` when we're explicitly checking for opaque type
     // recursion, and 'false' otherwise to avoid unecessary work.
     check_recursion: bool,
     tcx: TyCtxt<'tcx>,

src/test/ui/type-alias-impl-trait/opaque-type-in-predicate.rs

@@ -1,4 +1,5 @@
 // run-pass
+
 // Regression test for issue #65918 - checks that we do not
 // ICE when attempting to normalize a predicate containting
 // opaque types