Remove superfluous traversable impl for DefId

Author: eggyal

compiler/rustc_middle/src/ty/structural_impls.rs

@@ -408,6 +408,7 @@ TrivialLiftImpls! {
      bool,
      usize,
      u64,
+     ::rustc_hir::def_id::DefId,
      ::rustc_hir::Mutability,
      crate::ty::ParamConst,
      crate::ty::ParamTy,
@@ -430,7 +431,6 @@ TrivialTypeTraversalImpls! {
 // implementation and a lift implementation (the former only for TyCtxt<'_>
 // interners).
 TrivialTypeTraversalAndLiftImpls! {
-    ::rustc_hir::def_id::DefId,
     ::rustc_hir::Unsafety,
     ::rustc_target::spec::abi::Abi,
     crate::ty::ClosureKind,

compiler/rustc_type_ir/src/predicate_kind.rs

@@ -6,7 +6,7 @@ use std::ops::ControlFlow;
 
 use crate::fold::{FallibleTypeFolder, TypeFoldable};
 use crate::visit::{TypeVisitable, TypeVisitor};
-use crate::{HashStableContext, Interner};
+use crate::{HashStableContext, Interner, BoringTraversable};
 use crate::{TyDecoder, TyEncoder};
 
 /// A clause is something that can appear in where bounds or be inferred
@@ -370,7 +370,7 @@ where
 
 impl<I: Interner> TypeFoldable<I> for PredicateKind<I>
 where
-    I::DefId: TypeFoldable<I>,
+    I::DefId: BoringTraversable,
     I::Const: TypeFoldable<I>,
     I::GenericArgs: TypeFoldable<I>,
     I::Term: TypeFoldable<I>,
@@ -414,7 +414,7 @@ where
 
 impl<I: Interner> TypeVisitable<I> for PredicateKind<I>
 where
-    I::DefId: TypeVisitable<I>,
+    I::DefId: BoringTraversable,
     I::Const: TypeVisitable<I>,
     I::GenericArgs: TypeVisitable<I>,
     I::Term: TypeVisitable<I>,