Fix/suppress clippy warnings

Author: JohnTitor

src/mapping.rs

@@ -48,10 +48,10 @@ impl Hash for InherentEntry {
 
         // FIXME derive Hash again once AssocKind derives Hash again.
         match self.kind {
-            AssocKind::Const => 0u8.hash(hasher),
-            AssocKind::Fn => 1u8.hash(hasher),
-            AssocKind::OpaqueTy => 2u8.hash(hasher),
-            AssocKind::Type => 3u8.hash(hasher),
+            AssocKind::Const => 0_u8.hash(hasher),
+            AssocKind::Fn => 1_u8.hash(hasher),
+            AssocKind::OpaqueTy => 2_u8.hash(hasher),
+            AssocKind::Type => 3_u8.hash(hasher),
         }
 
         self.name.hash(hasher);

src/mismatch.rs

@@ -129,6 +129,8 @@ impl<'a, 'tcx> TypeRelation<'tcx> for MismatchRelation<'a, 'tcx> {
         Relate::relate(self, a, b)
     }
 
+    // Allow this since that lint is too pedantic here.
+    #[allow(clippy::similar_names)]
     fn tys(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) -> RelateResult<'tcx, Ty<'tcx>> {
         use rustc_middle::ty::TyKind;