Auto merge of #108340 - eggyal:remove_traversal_trait_aliases, r=oli-obk

Remove type-traversal trait aliases

#107924 moved the type traversal (folding and visiting) traits into the type library, but created trait aliases in `rustc_middle` to minimise both the API churn for trait consumers and the arising boilerplate.  As mentioned in that PR, an alternative approach of defining subtraits with blanket implementations of the respective supertraits was also considered at that time but was ruled out as not adding much value.

Unfortunately, it has since emerged that rust-analyzer has difficulty with these trait aliases at present, resulting in a degraded contributor experience (see the recent [r-a has become useless](https://rust-lang.zulipchat.com/#narrow/stream/182449-t-compiler.2Fhelp/topic/r-a.20has.20become.20useless) topic on the #t-compiler/help Zulip stream).

This PR removes the trait aliases, and accordingly the underlying type library traits are now used directly; they are parameterised by `TyCtxt<'tcx>` rather than just the `'tcx` lifetime, and imports have been updated to reflect the fact that the trait aliases' explicitly named traits are no longer automatically brought into scope.  These changes also roll-back the (no-longer required) workarounds to #107747 that were made in b409329c624b9e3bbd7d8e07697e2e9f861a45b6.

Since this PR is just a find+replace together with the changes necessary for compilation & tidy to pass, it's currently just one mega-commit.  Let me know if you'd like it broken up.

r? `@oli-obk`

192 files changed, 658 insertions, 569 deletions

diff --git a/compiler/rustc_borrowck/src/constraint_generation.rs b/compiler/rustc_borrowck/src/constraint_generation.rs
index 11b31c3f140..1427f5cb31d 100644
--- a/compiler/rustc_borrowck/src/constraint_generation.rs
+++ b/compiler/rustc_borrowck/src/constraint_generation.rs
@@ -9,7 +9,7 @@ use rustc_middle::mir::{
 };
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::visit::TypeVisitable;
-use rustc_middle::ty::{self, RegionVid, Ty};
+use rustc_middle::ty::{self, RegionVid, Ty, TyCtxt};
 
 use crate::{
     borrow_set::BorrowSet, facts::AllFacts, location::LocationTable, nll::ToRegionVid,
@@ -165,7 +165,7 @@ impl<'cx, 'tcx> ConstraintGeneration<'cx, 'tcx> {
     /// `location`.
     fn add_regular_live_constraint<T>(&mut self, live_ty: T, location: Location)
     where
-        T: TypeVisitable<'tcx>,
+        T: TypeVisitable<TyCtxt<'tcx>>,
     {
         debug!("add_regular_live_constraint(live_ty={:?}, location={:?})", live_ty, location);
 
diff --git a/compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs
index d51cc652bfd..68205fa4558 100644
--- a/compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs
@@ -106,7 +106,7 @@ impl<'tcx> ToUniverseInfo<'tcx>
     }
 }
 
-impl<'tcx, T: Copy + fmt::Display + TypeFoldable<'tcx> + 'tcx> ToUniverseInfo<'tcx>
+impl<'tcx, T: Copy + fmt::Display + TypeFoldable<TyCtxt<'tcx>> + 'tcx> ToUniverseInfo<'tcx>
     for Canonical<'tcx, ty::ParamEnvAnd<'tcx, type_op::Normalize<T>>>
 {
     fn to_universe_info(self, base_universe: ty::UniverseIndex) -> UniverseInfo<'tcx> {
@@ -258,7 +258,7 @@ struct NormalizeQuery<'tcx, T> {
 
 impl<'tcx, T> TypeOpInfo<'tcx> for NormalizeQuery<'tcx, T>
 where
-    T: Copy + fmt::Display + TypeFoldable<'tcx> + 'tcx,
+    T: Copy + fmt::Display + TypeFoldable<TyCtxt<'tcx>> + 'tcx,
 {
     fn fallback_error(
         &self,
diff --git a/compiler/rustc_borrowck/src/region_infer/mod.rs b/compiler/rustc_borrowck/src/region_infer/mod.rs
index 8c374c2164c..941da2dd3b5 100644
--- a/compiler/rustc_borrowck/src/region_infer/mod.rs
+++ b/compiler/rustc_borrowck/src/region_infer/mod.rs
@@ -17,7 +17,7 @@ use rustc_middle::mir::{
 };
 use rustc_middle::traits::ObligationCause;
 use rustc_middle::traits::ObligationCauseCode;
-use rustc_middle::ty::{self, RegionVid, Ty, TyCtxt, TypeFoldable};
+use rustc_middle::ty::{self, RegionVid, Ty, TyCtxt, TypeFoldable, TypeVisitableExt};
 use rustc_span::Span;
 
 use crate::{
@@ -1366,7 +1366,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     /// we use this kind of hacky solution.
     fn normalize_to_scc_representatives<T>(&self, tcx: TyCtxt<'tcx>, value: T) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         tcx.fold_regions(value, |r, _db| {
             let vid = self.to_region_vid(r);
diff --git a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
index 4ccdeeff72b..ae1d89de80e 100644
--- a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
+++ b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
@@ -6,7 +6,7 @@ use rustc_infer::infer::TyCtxtInferExt as _;
 use rustc_infer::infer::{DefiningAnchor, InferCtxt};
 use rustc_infer::traits::{Obligation, ObligationCause};
 use rustc_middle::ty::subst::{GenericArgKind, InternalSubsts};
-use rustc_middle::ty::visit::TypeVisitable;
+use rustc_middle::ty::visit::TypeVisitableExt;
 use rustc_middle::ty::{self, OpaqueHiddenType, OpaqueTypeKey, Ty, TyCtxt, TypeFoldable};
 use rustc_span::Span;
 use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _;
@@ -178,7 +178,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     /// region names in error messages.
     pub(crate) fn name_regions<T>(&self, tcx: TyCtxt<'tcx>, ty: T) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         tcx.fold_regions(ty, |region, _| match *region {
             ty::ReVar(vid) => {
diff --git a/compiler/rustc_borrowck/src/renumber.rs b/compiler/rustc_borrowck/src/renumber.rs
index 960dedc74ef..016f6f78dfa 100644
--- a/compiler/rustc_borrowck/src/renumber.rs
+++ b/compiler/rustc_borrowck/src/renumber.rs
@@ -38,7 +38,7 @@ pub(crate) fn renumber_regions<'tcx, T, F>(
     get_ctxt_fn: F,
 ) -> T
 where
-    T: TypeFoldable<'tcx>,
+    T: TypeFoldable<TyCtxt<'tcx>>,
     F: Fn() -> RegionCtxt,
 {
     infcx.tcx.fold_regions(value, |_region, _depth| {
@@ -89,7 +89,7 @@ struct NllVisitor<'a, 'tcx> {
 impl<'a, 'tcx> NllVisitor<'a, 'tcx> {
     fn renumber_regions<T, F>(&mut self, value: T, region_ctxt_fn: F) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
         F: Fn() -> RegionCtxt,
     {
         renumber_regions(self.infcx, value, region_ctxt_fn)
diff --git a/compiler/rustc_borrowck/src/type_check/canonical.rs b/compiler/rustc_borrowck/src/type_check/canonical.rs
index 2b81a35052d..1be20f18707 100644
--- a/compiler/rustc_borrowck/src/type_check/canonical.rs
+++ b/compiler/rustc_borrowck/src/type_check/canonical.rs
@@ -2,7 +2,7 @@ use std::fmt;
 
 use rustc_infer::infer::{canonical::Canonical, InferOk};
 use rustc_middle::mir::ConstraintCategory;
-use rustc_middle::ty::{self, ToPredicate, Ty, TypeFoldable};
+use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt, TypeFoldable};
 use rustc_span::def_id::DefId;
 use rustc_span::Span;
 use rustc_trait_selection::traits::query::type_op::{self, TypeOpOutput};
@@ -66,7 +66,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         canonical: &Canonical<'tcx, T>,
     ) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         let old_universe = self.infcx.universe();
 
diff --git a/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs b/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs
index 1dc6c42fbf7..504633c6a5c 100644
--- a/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs
+++ b/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs
@@ -6,8 +6,8 @@ use rustc_infer::infer::region_constraints::{GenericKind, VerifyBound};
 use rustc_infer::infer::{self, InferCtxt, SubregionOrigin};
 use rustc_middle::mir::{ClosureOutlivesSubject, ClosureRegionRequirements, ConstraintCategory};
 use rustc_middle::ty::subst::GenericArgKind;
-use rustc_middle::ty::TypeFoldable;
 use rustc_middle::ty::{self, TyCtxt};
+use rustc_middle::ty::{TypeFoldable, TypeVisitableExt};
 use rustc_span::{Span, DUMMY_SP};
 
 use crate::{
@@ -171,7 +171,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> {
     ///
     /// FIXME: This should get removed once higher ranked region obligations
     /// are dealt with during trait solving.
-    fn replace_placeholders_with_nll<T: TypeFoldable<'tcx>>(&mut self, value: T) -> T {
+    fn replace_placeholders_with_nll<T: TypeFoldable<TyCtxt<'tcx>>>(&mut self, value: T) -> T {
         if value.has_placeholders() {
             self.tcx.fold_regions(value, |r, _| match *r {
                 ty::RePlaceholder(placeholder) => {
diff --git a/compiler/rustc_borrowck/src/type_check/liveness/trace.rs b/compiler/rustc_borrowck/src/type_check/liveness/trace.rs
index 3ff5d188a3d..473c0596300 100644
--- a/compiler/rustc_borrowck/src/type_check/liveness/trace.rs
+++ b/compiler/rustc_borrowck/src/type_check/liveness/trace.rs
@@ -3,7 +3,7 @@ use rustc_index::bit_set::HybridBitSet;
 use rustc_index::interval::IntervalSet;
 use rustc_infer::infer::canonical::QueryRegionConstraints;
 use rustc_middle::mir::{BasicBlock, Body, ConstraintCategory, Local, Location};
-use rustc_middle::ty::{Ty, TypeVisitable};
+use rustc_middle::ty::{Ty, TyCtxt, TypeVisitable, TypeVisitableExt};
 use rustc_trait_selection::traits::query::dropck_outlives::DropckOutlivesResult;
 use rustc_trait_selection::traits::query::type_op::outlives::DropckOutlives;
 use rustc_trait_selection::traits::query::type_op::{TypeOp, TypeOpOutput};
@@ -477,7 +477,7 @@ impl<'tcx> LivenessContext<'_, '_, '_, 'tcx> {
     /// points `live_at`.
     fn add_use_live_facts_for(
         &mut self,
-        value: impl TypeVisitable<'tcx>,
+        value: impl TypeVisitable<TyCtxt<'tcx>>,
         live_at: &IntervalSet<PointIndex>,
     ) {
         debug!("add_use_live_facts_for(value={:?})", value);
@@ -542,7 +542,7 @@ impl<'tcx> LivenessContext<'_, '_, '_, 'tcx> {
     fn make_all_regions_live(
         elements: &RegionValueElements,
         typeck: &mut TypeChecker<'_, 'tcx>,
-        value: impl TypeVisitable<'tcx>,
+        value: impl TypeVisitable<TyCtxt<'tcx>>,
         live_at: &IntervalSet<PointIndex>,
     ) {
         debug!("make_all_regions_live(value={:?})", value);
diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs
index f14f8f1906b..eb0fa1b6859 100644
--- a/compiler/rustc_borrowck/src/type_check/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/mod.rs
@@ -30,7 +30,7 @@ use rustc_middle::mir::*;
 use rustc_middle::ty::adjustment::PointerCast;
 use rustc_middle::ty::cast::CastTy;
 use rustc_middle::ty::subst::{SubstsRef, UserSubsts};
-use rustc_middle::ty::visit::TypeVisitable;
+use rustc_middle::ty::visit::TypeVisitableExt;
 use rustc_middle::ty::{
     self, Binder, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, Dynamic,
     OpaqueHiddenType, OpaqueTypeKey, RegionVid, Ty, TyCtxt, UserType, UserTypeAnnotationIndex,
diff --git a/compiler/rustc_borrowck/src/universal_regions.rs b/compiler/rustc_borrowck/src/universal_regions.rs
index f3ca896cd0d..3e8731755fc 100644
--- a/compiler/rustc_borrowck/src/universal_regions.rs
+++ b/compiler/rustc_borrowck/src/universal_regions.rs
@@ -728,7 +728,7 @@ trait InferCtxtExt<'tcx> {
         value: T,
     ) -> T
     where
-        T: TypeFoldable<'tcx>;
+        T: TypeFoldable<TyCtxt<'tcx>>;
 
     fn replace_bound_regions_with_nll_infer_vars<T>(
         &self,
@@ -738,7 +738,7 @@ trait InferCtxtExt<'tcx> {
         indices: &mut UniversalRegionIndices<'tcx>,
     ) -> T
     where
-        T: TypeFoldable<'tcx>;
+        T: TypeFoldable<TyCtxt<'tcx>>;
 
     fn replace_late_bound_regions_with_nll_infer_vars_in_recursive_scope(
         &self,
@@ -761,7 +761,7 @@ impl<'cx, 'tcx> InferCtxtExt<'tcx> for BorrowckInferCtxt<'cx, 'tcx> {
         value: T,
     ) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         self.infcx.tcx.fold_regions(value, |region, _depth| {
             let name = match region.get_name() {
@@ -785,7 +785,7 @@ impl<'cx, 'tcx> InferCtxtExt<'tcx> for BorrowckInferCtxt<'cx, 'tcx> {
         indices: &mut UniversalRegionIndices<'tcx>,
     ) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         let (value, _map) = self.tcx.replace_late_bound_regions(value, |br| {
             debug!(?br);
@@ -906,7 +906,7 @@ impl<'tcx> UniversalRegionIndices<'tcx> {
     /// returned by `to_region_vid`.
     pub fn fold_to_region_vids<T>(&self, tcx: TyCtxt<'tcx>, value: T) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         tcx.fold_regions(value, |region, _| tcx.mk_re_var(self.to_region_vid(region)))
     }
diff --git a/compiler/rustc_codegen_cranelift/src/common.rs b/compiler/rustc_codegen_cranelift/src/common.rs
index a8be0d32cc8..722e2754e83 100644
--- a/compiler/rustc_codegen_cranelift/src/common.rs
+++ b/compiler/rustc_codegen_cranelift/src/common.rs
@@ -374,7 +374,7 @@ impl<'tcx> HasTargetSpec for FunctionCx<'_, '_, 'tcx> {
 impl<'tcx> FunctionCx<'_, '_, 'tcx> {
     pub(crate) fn monomorphize<T>(&self, value: T) -> T
     where
-        T: TypeFoldable<'tcx> + Copy,
+        T: TypeFoldable<TyCtxt<'tcx>> + Copy,
     {
         self.instance.subst_mir_and_normalize_erasing_regions(
             self.tcx,
diff --git a/compiler/rustc_codegen_cranelift/src/lib.rs b/compiler/rustc_codegen_cranelift/src/lib.rs
index 5ba568bfd6e..80ce3dc9328 100644
--- a/compiler/rustc_codegen_cranelift/src/lib.rs
+++ b/compiler/rustc_codegen_cranelift/src/lib.rs
@@ -86,7 +86,7 @@ mod prelude {
     pub(crate) use rustc_middle::ty::layout::{self, LayoutOf, TyAndLayout};
     pub(crate) use rustc_middle::ty::{
         self, FloatTy, Instance, InstanceDef, IntTy, ParamEnv, Ty, TyCtxt, TypeAndMut,
-        TypeFoldable, UintTy,
+        TypeFoldable, TypeVisitableExt, UintTy,
     };
     pub(crate) use rustc_target::abi::{Abi, Scalar, Size, VariantIdx};
 
diff --git a/compiler/rustc_codegen_gcc/src/callee.rs b/compiler/rustc_codegen_gcc/src/callee.rs
index c1041125ecc..9e3a22ee05d 100644
--- a/compiler/rustc_codegen_gcc/src/callee.rs
+++ b/compiler/rustc_codegen_gcc/src/callee.rs
@@ -1,6 +1,6 @@
 use gccjit::{FunctionType, RValue};
 use rustc_codegen_ssa::traits::BaseTypeMethods;
-use rustc_middle::ty::{self, Instance, TypeVisitable};
+use rustc_middle::ty::{self, Instance, TypeVisitableExt};
 use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt};
 
 use crate::abi::FnAbiGccExt;
diff --git a/compiler/rustc_codegen_gcc/src/mono_item.rs b/compiler/rustc_codegen_gcc/src/mono_item.rs
index 9468a1ef4bb..a7c868354fb 100644
--- a/compiler/rustc_codegen_gcc/src/mono_item.rs
+++ b/compiler/rustc_codegen_gcc/src/mono_item.rs
@@ -1,7 +1,7 @@
 use rustc_codegen_ssa::traits::PreDefineMethods;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use rustc_middle::mir::mono::{Linkage, Visibility};
-use rustc_middle::ty::{self, Instance, TypeVisitable};
+use rustc_middle::ty::{self, Instance, TypeVisitableExt};
 use rustc_middle::ty::layout::{FnAbiOf, LayoutOf};
 use rustc_span::def_id::DefId;
 
diff --git a/compiler/rustc_codegen_gcc/src/type_of.rs b/compiler/rustc_codegen_gcc/src/type_of.rs
index 1326af670cd..ea2ce765053 100644
--- a/compiler/rustc_codegen_gcc/src/type_of.rs
+++ b/compiler/rustc_codegen_gcc/src/type_of.rs
@@ -3,7 +3,7 @@ use std::fmt::Write;
 use gccjit::{Struct, Type};
 use crate::rustc_codegen_ssa::traits::{BaseTypeMethods, DerivedTypeMethods, LayoutTypeMethods};
 use rustc_middle::bug;
-use rustc_middle::ty::{self, Ty, TypeVisitable};
+use rustc_middle::ty::{self, Ty, TypeVisitableExt};
 use rustc_middle::ty::layout::{FnAbiOf, LayoutOf, TyAndLayout};
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_target::abi::{self, Abi, F32, F64, FieldsShape, Int, Integer, Pointer, PointeeInfo, Size, TyAbiInterface, Variants};
diff --git a/compiler/rustc_codegen_llvm/src/callee.rs b/compiler/rustc_codegen_llvm/src/callee.rs
index f1d01a4602a..6ee2a05ffd7 100644
--- a/compiler/rustc_codegen_llvm/src/callee.rs
+++ b/compiler/rustc_codegen_llvm/src/callee.rs
@@ -13,7 +13,7 @@ use crate::value::Value;
 use rustc_codegen_ssa::traits::*;
 
 use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt};
-use rustc_middle::ty::{self, Instance, TypeVisitable};
+use rustc_middle::ty::{self, Instance, TypeVisitableExt};
 
 /// Codegens a reference to a fn/method item, monomorphizing and
 /// inlining as it goes.
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
index cef403b9f8b..5392534cfcb 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
@@ -27,7 +27,7 @@ use rustc_index::vec::IndexVec;
 use rustc_middle::mir;
 use rustc_middle::ty::layout::LayoutOf;
 use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
-use rustc_middle::ty::{self, Instance, ParamEnv, Ty, TypeVisitable};
+use rustc_middle::ty::{self, Instance, ParamEnv, Ty, TypeVisitableExt};
 use rustc_session::config::{self, DebugInfo};
 use rustc_session::Session;
 use rustc_span::symbol::Symbol;
diff --git a/compiler/rustc_codegen_llvm/src/mono_item.rs b/compiler/rustc_codegen_llvm/src/mono_item.rs
index 76f692b2016..d0ae36349df 100644
--- a/compiler/rustc_codegen_llvm/src/mono_item.rs
+++ b/compiler/rustc_codegen_llvm/src/mono_item.rs
@@ -9,7 +9,7 @@ use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 pub use rustc_middle::mir::mono::MonoItem;
 use rustc_middle::mir::mono::{Linkage, Visibility};
 use rustc_middle::ty::layout::{FnAbiOf, LayoutOf};
-use rustc_middle::ty::{self, Instance, TypeVisitable};
+use rustc_middle::ty::{self, Instance, TypeVisitableExt};
 use rustc_session::config::CrateType;
 use rustc_target::spec::RelocModel;
 
diff --git a/compiler/rustc_codegen_llvm/src/type_of.rs b/compiler/rustc_codegen_llvm/src/type_of.rs
index 9cda24bab87..e264ce78f0d 100644
--- a/compiler/rustc_codegen_llvm/src/type_of.rs
+++ b/compiler/rustc_codegen_llvm/src/type_of.rs
@@ -5,7 +5,7 @@ use rustc_codegen_ssa::traits::*;
 use rustc_middle::bug;
 use rustc_middle::ty::layout::{FnAbiOf, LayoutOf, TyAndLayout};
 use rustc_middle::ty::print::{with_no_trimmed_paths, with_no_visible_paths};
-use rustc_middle::ty::{self, Ty, TypeVisitable};
+use rustc_middle::ty::{self, Ty, TypeVisitableExt};
 use rustc_target::abi::{Abi, Align, FieldsShape};
 use rustc_target::abi::{Int, Pointer, F32, F64};
 use rustc_target::abi::{PointeeInfo, Scalar, Size, TyAbiInterface, Variants};
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index e105322a0b4..cdc3e1dc237 100644
--- a/compiler/rustc_codegen_ssa/src/mir/block.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -16,7 +16,7 @@ use rustc_index::vec::Idx;
 use rustc_middle::mir::{self, AssertKind, SwitchTargets};
 use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf};
 use rustc_middle::ty::print::{with_no_trimmed_paths, with_no_visible_paths};
-use rustc_middle::ty::{self, Instance, Ty, TypeVisitable};
+use rustc_middle::ty::{self, Instance, Ty, TypeVisitableExt};
 use rustc_session::config::OptLevel;
 use rustc_span::source_map::Span;
 use rustc_span::{sym, Symbol};
diff --git a/compiler/rustc_codegen_ssa/src/mir/mod.rs b/compiler/rustc_codegen_ssa/src/mir/mod.rs
index eec91ffa44a..2ec9fdbf44f 100644
--- a/compiler/rustc_codegen_ssa/src/mir/mod.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/mod.rs
@@ -3,7 +3,7 @@ use crate::traits::*;
 use rustc_middle::mir;
 use rustc_middle::mir::interpret::ErrorHandled;
 use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt, TyAndLayout};
-use rustc_middle::ty::{self, Instance, Ty, TypeFoldable};
+use rustc_middle::ty::{self, Instance, Ty, TyCtxt, TypeFoldable, TypeVisitableExt};
 use rustc_target::abi::call::{FnAbi, PassMode};
 
 use std::iter;
@@ -105,7 +105,7 @@ pub struct FunctionCx<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> {
 impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     pub fn monomorphize<T>(&self, value: T) -> T
     where
-        T: Copy + TypeFoldable<'tcx>,
+        T: Copy + TypeFoldable<TyCtxt<'tcx>>,
     {
         debug!("monomorphize: self.instance={:?}", self.instance);
         self.instance.subst_mir_and_normalize_erasing_regions(
diff --git a/compiler/rustc_const_eval/src/interpret/eval_context.rs b/compiler/rustc_const_eval/src/interpret/eval_context.rs
index 24b157054d3..3db102e484d 100644
--- a/compiler/rustc_const_eval/src/interpret/eval_context.rs
+++ b/compiler/rustc_const_eval/src/interpret/eval_context.rs
@@ -489,7 +489,9 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
 
     /// Call this on things you got out of the MIR (so it is as generic as the current
     /// stack frame), to bring it into the proper environment for this interpreter.
-    pub(super) fn subst_from_current_frame_and_normalize_erasing_regions<T: TypeFoldable<'tcx>>(
+    pub(super) fn subst_from_current_frame_and_normalize_erasing_regions<
+        T: TypeFoldable<TyCtxt<'tcx>>,
+    >(
         &self,
         value: T,
     ) -> Result<T, InterpError<'tcx>> {
@@ -498,7 +500,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
 
     /// Call this on things you got out of the MIR (so it is as generic as the provided
     /// stack frame), to bring it into the proper environment for this interpreter.
-    pub(super) fn subst_from_frame_and_normalize_erasing_regions<T: TypeFoldable<'tcx>>(
+    pub(super) fn subst_from_frame_and_normalize_erasing_regions<T: TypeFoldable<TyCtxt<'tcx>>>(
         &self,
         frame: &Frame<'mir, 'tcx, M::Provenance, M::FrameExtra>,
         value: T,
diff --git a/compiler/rustc_const_eval/src/interpret/util.rs b/compiler/rustc_const_eval/src/interpret/util.rs
index 581cb6421f7..bf2b4ee69ab 100644
--- a/compiler/rustc_const_eval/src/interpret/util.rs
+++ b/compiler/rustc_const_eval/src/interpret/util.rs
@@ -1,5 +1,7 @@
 use rustc_middle::mir::interpret::InterpResult;
-use rustc_middle::ty::{self, ir::TypeVisitor, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable};
+use rustc_middle::ty::{
+    self, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor,
+};
 use std::ops::ControlFlow;
 
 /// Checks whether a type contains generic parameters which require substitution.
@@ -9,7 +11,7 @@ use std::ops::ControlFlow;
 /// case these parameters are unused.
 pub(crate) fn ensure_monomorphic_enough<'tcx, T>(tcx: TyCtxt<'tcx>, ty: T) -> InterpResult<'tcx>
 where
-    T: TypeVisitable<'tcx>,
+    T: TypeVisitable<TyCtxt<'tcx>>,
 {
     debug!("ensure_monomorphic_enough: ty={:?}", ty);
     if !ty.needs_subst() {
diff --git a/compiler/rustc_const_eval/src/transform/check_consts/check.rs b/compiler/rustc_const_eval/src/transform/check_consts/check.rs
index faf741de60a..e4366f655e4 100644
--- a/compiler/rustc_const_eval/src/transform/check_consts/check.rs
+++ b/compiler/rustc_const_eval/src/transform/check_consts/check.rs
@@ -10,7 +10,7 @@ use rustc_middle::mir::visit::{MutatingUseContext, NonMutatingUseContext, PlaceC
 use rustc_middle::mir::*;
 use rustc_middle::ty::subst::{GenericArgKind, InternalSubsts};
 use rustc_middle::ty::{self, adjustment::PointerCast, Instance, InstanceDef, Ty, TyCtxt};
-use rustc_middle::ty::{Binder, TraitRef, TypeVisitable};
+use rustc_middle::ty::{Binder, TraitRef, TypeVisitableExt};
 use rustc_mir_dataflow::{self, Analysis};
 use rustc_span::{sym, Span, Symbol};
 use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _;
diff --git a/compiler/rustc_const_eval/src/transform/promote_consts.rs b/compiler/rustc_const_eval/src/transform/promote_consts.rs
index 19367d708ee..ba08f5d30d9 100644
--- a/compiler/rustc_const_eval/src/transform/promote_consts.rs
+++ b/compiler/rustc_const_eval/src/transform/promote_consts.rs
@@ -18,7 +18,7 @@ use rustc_middle::mir::traversal::ReversePostorderIter;
 use rustc_middle::mir::visit::{MutVisitor, MutatingUseContext, PlaceContext, Visitor};
 use rustc_middle::mir::*;
 use rustc_middle::ty::subst::InternalSubsts;
-use rustc_middle::ty::{self, List, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, List, TyCtxt, TypeVisitableExt};
 use rustc_span::Span;
 
 use rustc_index::vec::{Idx, IndexVec};
diff --git a/compiler/rustc_const_eval/src/transform/validate.rs b/compiler/rustc_const_eval/src/transform/validate.rs
index 67dbf29da3b..3af2d0c4e66 100644
--- a/compiler/rustc_const_eval/src/transform/validate.rs
+++ b/compiler/rustc_const_eval/src/transform/validate.rs
@@ -13,7 +13,7 @@ use rustc_middle::mir::{
     RetagKind, RuntimePhase, Rvalue, SourceScope, Statement, StatementKind, Terminator,
     TerminatorKind, UnOp, START_BLOCK,
 };
-use rustc_middle::ty::{self, InstanceDef, ParamEnv, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, InstanceDef, ParamEnv, Ty, TyCtxt, TypeVisitableExt};
 use rustc_mir_dataflow::impls::MaybeStorageLive;
 use rustc_mir_dataflow::storage::always_storage_live_locals;
 use rustc_mir_dataflow::{Analysis, ResultsCursor};
diff --git a/compiler/rustc_hir_analysis/src/astconv/mod.rs b/compiler/rustc_hir_analysis/src/astconv/mod.rs
index c0cd54cc916..3764b9f68f5 100644
--- a/compiler/rustc_hir_analysis/src/astconv/mod.rs
+++ b/compiler/rustc_hir_analysis/src/astconv/mod.rs
@@ -35,7 +35,7 @@ use rustc_middle::middle::stability::AllowUnstable;
 use rustc_middle::ty::subst::{self, GenericArgKind, InternalSubsts, SubstsRef};
 use rustc_middle::ty::DynKind;
 use rustc_middle::ty::GenericParamDefKind;
-use rustc_middle::ty::{self, Const, DefIdTree, IsSuggestable, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, Const, DefIdTree, IsSuggestable, Ty, TyCtxt, TypeVisitableExt};
 use rustc_session::lint::builtin::{AMBIGUOUS_ASSOCIATED_ITEMS, BARE_TRAIT_OBJECTS};
 use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::edition::Edition;
diff --git a/compiler/rustc_hir_analysis/src/autoderef.rs b/compiler/rustc_hir_analysis/src/autoderef.rs
index a5c96a8b016..ba2d4319af6 100644
--- a/compiler/rustc_hir_analysis/src/autoderef.rs
+++ b/compiler/rustc_hir_analysis/src/autoderef.rs
@@ -3,7 +3,7 @@ use crate::traits::query::evaluate_obligation::InferCtxtExt;
 use crate::traits::NormalizeExt;
 use crate::traits::{self, TraitEngine, TraitEngineExt};
 use rustc_infer::infer::InferCtxt;
-use rustc_middle::ty::TypeVisitable;
+use rustc_middle::ty::TypeVisitableExt;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_session::Limit;
 use rustc_span::def_id::LocalDefId;
diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs
index 04396c883d3..3ca886f11d1 100644
--- a/compiler/rustc_hir_analysis/src/check/check.rs
+++ b/compiler/rustc_hir_analysis/src/check/check.rs
@@ -23,6 +23,7 @@ use rustc_middle::ty::subst::GenericArgKind;
 use rustc_middle::ty::util::{Discr, IntTypeExt};
 use rustc_middle::ty::{
     self, AdtDef, DefIdTree, ParamEnv, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable,
+    TypeVisitableExt,
 };
 use rustc_session::lint::builtin::{UNINHABITED_STATIC, UNSUPPORTED_CALLING_CONVENTIONS};
 use rustc_span::symbol::sym;
@@ -255,7 +256,7 @@ pub(super) fn check_opaque_for_inheriting_lifetimes(
         selftys: Vec<(Span, Option<String>)>,
     }
 
-    impl<'tcx> ty::visit::ir::TypeVisitor<TyCtxt<'tcx>> for ProhibitOpaqueVisitor<'tcx> {
+    impl<'tcx> ty::visit::TypeVisitor<TyCtxt<'tcx>> for ProhibitOpaqueVisitor<'tcx> {
         type BreakTy = Ty<'tcx>;
 
         fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
@@ -1418,7 +1419,7 @@ fn opaque_type_cycle_error(
                     opaques: Vec<DefId>,
                     closures: Vec<DefId>,
                 }
-                impl<'tcx> ty::visit::ir::TypeVisitor<TyCtxt<'tcx>> for OpaqueTypeCollector {
+                impl<'tcx> ty::visit::TypeVisitor<TyCtxt<'tcx>> for OpaqueTypeCollector {
                     fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
                         match *t.kind() {
                             ty::Alias(ty::Opaque, ty::AliasTy { def_id: def, .. }) => {
diff --git a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
index a9fcc8e6250..50005582f7c 100644
--- a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
+++ b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
@@ -16,7 +16,8 @@ use rustc_infer::traits::util;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::util::ExplicitSelf;
 use rustc_middle::ty::{
-    self, ir::TypeFolder, DefIdTree, InternalSubsts, Ty, TypeFoldable, TypeSuperFoldable,
+    self, DefIdTree, InternalSubsts, Ty, TypeFoldable, TypeFolder, TypeSuperFoldable,
+    TypeVisitableExt,
 };
 use rustc_middle::ty::{GenericParamDefKind, ToPredicate, TyCtxt};
 use rustc_span::Span;
diff --git a/compiler/rustc_hir_analysis/src/check/intrinsicck.rs b/compiler/rustc_hir_analysis/src/check/intrinsicck.rs
index b3e76010da3..b1d5a27be93 100644
--- a/compiler/rustc_hir_analysis/src/check/intrinsicck.rs
+++ b/compiler/rustc_hir_analysis/src/check/intrinsicck.rs
@@ -1,7 +1,7 @@
 use rustc_ast::InlineAsmTemplatePiece;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
-use rustc_middle::ty::{self, Article, FloatTy, IntTy, Ty, TyCtxt, TypeVisitable, UintTy};
+use rustc_middle::ty::{self, Article, FloatTy, IntTy, Ty, TyCtxt, TypeVisitableExt, UintTy};
 use rustc_session::lint;
 use rustc_span::def_id::LocalDefId;
 use rustc_span::{Symbol, DUMMY_SP};
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
index 83b33321a52..25be62534a5 100644
--- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs
+++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
@@ -16,8 +16,8 @@ use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::trait_def::TraitSpecializationKind;
 use rustc_middle::ty::{
-    self, ir::TypeVisitor, AdtKind, GenericParamDefKind, Ty, TyCtxt, TypeFoldable,
-    TypeSuperVisitable,
+    self, AdtKind, GenericParamDefKind, Ty, TyCtxt, TypeFoldable, TypeSuperVisitable,
+    TypeVisitable, TypeVisitableExt, TypeVisitor,
 };
 use rustc_middle::ty::{GenericArgKind, InternalSubsts};
 use rustc_session::parse::feature_err;
@@ -56,7 +56,7 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
     // `ObligationCtxt::normalize`, but provides a nice `ObligationCauseCode`.
     fn normalize<T>(&self, span: Span, loc: Option<WellFormedLoc>, value: T) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         self.ocx.normalize(
             &ObligationCause::new(span, self.body_def_id, ObligationCauseCode::WellFormed(loc)),
@@ -510,7 +510,7 @@ fn augment_param_env<'tcx>(
 ///     fn into_iter<'a>(&'a self) -> Self::Iter<'a>;
 /// }
 /// ```
-fn gather_gat_bounds<'tcx, T: TypeFoldable<'tcx>>(
+fn gather_gat_bounds<'tcx, T: TypeFoldable<TyCtxt<'tcx>>>(
     tcx: TyCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
     item_def_id: hir::OwnerId,
@@ -708,7 +708,7 @@ struct GATSubstCollector<'tcx> {
 }
 
 impl<'tcx> GATSubstCollector<'tcx> {
-    fn visit<T: TypeFoldable<'tcx>>(
+    fn visit<T: TypeFoldable<TyCtxt<'tcx>>>(
         gat: DefId,
         t: T,
     ) -> (FxHashSet<(ty::Region<'tcx>, usize)>, FxHashSet<(Ty<'tcx>, usize)>) {
@@ -1382,7 +1382,7 @@ fn check_where_clauses<'tcx>(wfcx: &WfCheckingCtxt<'_, 'tcx>, span: Span, def_id
             struct CountParams {
                 params: FxHashSet<u32>,
             }
-            impl<'tcx> ty::visit::ir::TypeVisitor<TyCtxt<'tcx>> for CountParams {
+            impl<'tcx> ty::visit::TypeVisitor<TyCtxt<'tcx>> for CountParams {
                 type BreakTy = ();
 
                 fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
diff --git a/compiler/rustc_hir_analysis/src/coherence/builtin.rs b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
index 51c5f297051..875c5f1fd00 100644
--- a/compiler/rustc_hir_analysis/src/coherence/builtin.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
@@ -11,7 +11,7 @@ use rustc_infer::infer::outlives::env::OutlivesEnvironment;
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::infer::{self, RegionResolutionError};
 use rustc_middle::ty::adjustment::CoerceUnsizedInfo;
-use rustc_middle::ty::{self, suggest_constraining_type_params, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, suggest_constraining_type_params, Ty, TyCtxt, TypeVisitableExt};
 use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt;
 use rustc_trait_selection::traits::misc::{
     type_allowed_to_implement_copy, CopyImplementationError, InfringingFieldsReason,
diff --git a/compiler/rustc_hir_analysis/src/coherence/mod.rs b/compiler/rustc_hir_analysis/src/coherence/mod.rs
index bbde59c953a..23490bc091c 100644
--- a/compiler/rustc_hir_analysis/src/coherence/mod.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/mod.rs
@@ -8,7 +8,7 @@
 use rustc_errors::{error_code, struct_span_err};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::{self, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, TyCtxt, TypeVisitableExt};
 use rustc_span::sym;
 use rustc_trait_selection::traits;
 
diff --git a/compiler/rustc_hir_analysis/src/coherence/orphan.rs b/compiler/rustc_hir_analysis/src/coherence/orphan.rs
index f0a0e7e3e92..52c4a376fb2 100644
--- a/compiler/rustc_hir_analysis/src/coherence/orphan.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/orphan.rs
@@ -8,7 +8,8 @@ use rustc_hir as hir;
 use rustc_middle::ty::subst::InternalSubsts;
 use rustc_middle::ty::util::IgnoreRegions;
 use rustc_middle::ty::{
-    self, ir::TypeVisitor, AliasKind, ImplPolarity, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable,
+    self, AliasKind, ImplPolarity, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitableExt,
+    TypeVisitor,
 };
 use rustc_session::lint;
 use rustc_span::def_id::{DefId, LocalDefId};
diff --git a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
index e977767e024..6c00b8ff7bd 100644
--- a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
+++ b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
@@ -17,7 +17,7 @@ use rustc_hir::{GenericArg, GenericParam, GenericParamKind, HirIdMap, LifetimeNa
 use rustc_middle::bug;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::resolve_bound_vars::*;
-use rustc_middle::ty::{self, ir::TypeVisitor, DefIdTree, TyCtxt, TypeSuperVisitable};
+use rustc_middle::ty::{self, DefIdTree, TyCtxt, TypeSuperVisitable, TypeVisitor};
 use rustc_session::lint;
 use rustc_span::def_id::DefId;
 use rustc_span::symbol::{sym, Ident};
diff --git a/compiler/rustc_hir_analysis/src/collect/type_of.rs b/compiler/rustc_hir_analysis/src/collect/type_of.rs
index a3bc0082ef2..c013f1bdb31 100644
--- a/compiler/rustc_hir_analysis/src/collect/type_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/type_of.rs
@@ -9,7 +9,7 @@ use rustc_middle::ty::print::with_forced_trimmed_paths;
 use rustc_middle::ty::subst::InternalSubsts;
 use rustc_middle::ty::util::IntTypeExt;
 use rustc_middle::ty::{
-    self, ir::TypeFolder, DefIdTree, IsSuggestable, Ty, TyCtxt, TypeSuperFoldable, TypeVisitable,
+    self, DefIdTree, IsSuggestable, Ty, TyCtxt, TypeFolder, TypeSuperFoldable, TypeVisitableExt,
 };
 use rustc_span::symbol::Ident;
 use rustc_span::{Span, DUMMY_SP};
diff --git a/compiler/rustc_hir_analysis/src/constrained_generic_params.rs b/compiler/rustc_hir_analysis/src/constrained_generic_params.rs
index 072676c400d..e18b0f08279 100644
--- a/compiler/rustc_hir_analysis/src/constrained_generic_params.rs
+++ b/compiler/rustc_hir_analysis/src/constrained_generic_params.rs
@@ -1,5 +1,5 @@
 use rustc_data_structures::fx::FxHashSet;
-use rustc_middle::ty::visit::{ir::TypeVisitor, TypeSuperVisitable, TypeVisitable};
+use rustc_middle::ty::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitor};
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::source_map::Span;
 use std::ops::ControlFlow;
@@ -43,7 +43,7 @@ pub fn parameters_for_impl<'tcx>(
 /// of parameters whose values are needed in order to constrain `ty` - these
 /// differ, with the latter being a superset, in the presence of projections.
 pub fn parameters_for<'tcx>(
-    t: &impl TypeVisitable<'tcx>,
+    t: &impl TypeVisitable<TyCtxt<'tcx>>,
     include_nonconstraining: bool,
 ) -> Vec<Parameter> {
     let mut collector = ParameterCollector { parameters: vec![], include_nonconstraining };
diff --git a/compiler/rustc_hir_analysis/src/hir_wf_check.rs b/compiler/rustc_hir_analysis/src/hir_wf_check.rs
index 8fc4610ae85..e330fcc7857 100644
--- a/compiler/rustc_hir_analysis/src/hir_wf_check.rs
+++ b/compiler/rustc_hir_analysis/src/hir_wf_check.rs
@@ -5,7 +5,7 @@ use rustc_hir::{ForeignItem, ForeignItemKind};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::traits::{ObligationCause, WellFormedLoc};
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::{self, ir::TypeFolder, Region, TyCtxt, TypeFoldable};
+use rustc_middle::ty::{self, Region, TyCtxt, TypeFoldable, TypeFolder};
 use rustc_span::def_id::LocalDefId;
 use rustc_trait_selection::traits;
 
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check.rs b/compiler/rustc_hir_analysis/src/impl_wf_check.rs
index 8ab9964d810..82a96f8e674 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check.rs
@@ -16,7 +16,7 @@ use rustc_errors::struct_span_err;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalDefId;
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::{self, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, TyCtxt, TypeVisitableExt};
 use rustc_span::{Span, Symbol};
 
 mod min_specialization;
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
index 4741e4b095d..daa5d15704d 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
@@ -76,7 +76,7 @@ use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::traits::specialization_graph::Node;
 use rustc_middle::ty::subst::{GenericArg, InternalSubsts, SubstsRef};
 use rustc_middle::ty::trait_def::TraitSpecializationKind;
-use rustc_middle::ty::{self, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, TyCtxt, TypeVisitableExt};
 use rustc_span::Span;
 use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt;
 use rustc_trait_selection::traits::outlives_bounds::InferCtxtExt as _;
diff --git a/compiler/rustc_hir_analysis/src/structured_errors/missing_cast_for_variadic_arg.rs b/compiler/rustc_hir_analysis/src/structured_errors/missing_cast_for_variadic_arg.rs
index 324df313ef1..089491bef5e 100644
--- a/compiler/rustc_hir_analysis/src/structured_errors/missing_cast_for_variadic_arg.rs
+++ b/compiler/rustc_hir_analysis/src/structured_errors/missing_cast_for_variadic_arg.rs
@@ -1,6 +1,6 @@
 use crate::structured_errors::StructuredDiagnostic;
 use rustc_errors::{Applicability, DiagnosticBuilder, DiagnosticId, ErrorGuaranteed};
-use rustc_middle::ty::{Ty, TypeVisitable};
+use rustc_middle::ty::{Ty, TypeVisitableExt};
 use rustc_session::Session;
 use rustc_span::Span;
 
diff --git a/compiler/rustc_hir_analysis/src/structured_errors/sized_unsized_cast.rs b/compiler/rustc_hir_analysis/src/structured_errors/sized_unsized_cast.rs
index bb608805488..3b9fb367813 100644
--- a/compiler/rustc_hir_analysis/src/structured_errors/sized_unsized_cast.rs
+++ b/compiler/rustc_hir_analysis/src/structured_errors/sized_unsized_cast.rs
@@ -1,6 +1,6 @@
 use crate::structured_errors::StructuredDiagnostic;
 use rustc_errors::{DiagnosticBuilder, DiagnosticId, ErrorGuaranteed};
-use rustc_middle::ty::{Ty, TypeVisitable};
+use rustc_middle::ty::{Ty, TypeVisitableExt};
 use rustc_session::Session;
 use rustc_span::Span;
 
diff --git a/compiler/rustc_hir_analysis/src/variance/mod.rs b/compiler/rustc_hir_analysis/src/variance/mod.rs
index fb63bf22474..5d5c8ca604a 100644
--- a/compiler/rustc_hir_analysis/src/variance/mod.rs
+++ b/compiler/rustc_hir_analysis/src/variance/mod.rs
@@ -7,10 +7,8 @@ use rustc_arena::DroplessArena;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_middle::ty::query::Providers;
-#[cfg(not(bootstrap))]
-use rustc_middle::ty::TypeVisitable;
 use rustc_middle::ty::{self, CrateVariancesMap, SubstsRef, Ty, TyCtxt};
-use rustc_middle::ty::{DefIdTree, TypeSuperVisitable};
+use rustc_middle::ty::{DefIdTree, TypeSuperVisitable, TypeVisitable};
 use std::ops::ControlFlow;
 
 /// Defines the `TermsContext` basically houses an arena where we can
@@ -101,7 +99,7 @@ fn variance_of_opaque(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Varianc
         }
     }
 
-    impl<'tcx> ty::ir::TypeVisitor<TyCtxt<'tcx>> for OpaqueTypeLifetimeCollector<'tcx> {
+    impl<'tcx> ty::TypeVisitor<TyCtxt<'tcx>> for OpaqueTypeLifetimeCollector<'tcx> {
         #[instrument(level = "trace", skip(self), ret)]
         fn visit_region(&mut self, r: ty::Region<'tcx>) -> ControlFlow<Self::BreakTy> {
             if let ty::RegionKind::ReEarlyBound(ebr) = r.kind() {
diff --git a/compiler/rustc_hir_typeck/src/callee.rs b/compiler/rustc_hir_typeck/src/callee.rs
index 06b2b2451f0..ebb08a0cc04 100644
--- a/compiler/rustc_hir_typeck/src/callee.rs
+++ b/compiler/rustc_hir_typeck/src/callee.rs
@@ -21,7 +21,7 @@ use rustc_middle::ty::adjustment::{
     Adjust, Adjustment, AllowTwoPhase, AutoBorrow, AutoBorrowMutability,
 };
 use rustc_middle::ty::SubstsRef;
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::symbol::{sym, Ident};
 use rustc_span::Span;
diff --git a/compiler/rustc_hir_typeck/src/cast.rs b/compiler/rustc_hir_typeck/src/cast.rs
index 8e21c084841..316c2a7eeeb 100644
--- a/compiler/rustc_hir_typeck/src/cast.rs
+++ b/compiler/rustc_hir_typeck/src/cast.rs
@@ -41,7 +41,7 @@ use rustc_middle::mir::Mutability;
 use rustc_middle::ty::adjustment::AllowTwoPhase;
 use rustc_middle::ty::cast::{CastKind, CastTy};
 use rustc_middle::ty::error::TypeError;
-use rustc_middle::ty::{self, Ty, TypeAndMut, TypeVisitable, VariantDef};
+use rustc_middle::ty::{self, Ty, TypeAndMut, TypeVisitableExt, VariantDef};
 use rustc_session::lint;
 use rustc_session::Session;
 use rustc_span::def_id::{DefId, LOCAL_CRATE};
diff --git a/compiler/rustc_hir_typeck/src/closure.rs b/compiler/rustc_hir_typeck/src/closure.rs
index c289eae8d27..0eff3a2f9c2 100644
--- a/compiler/rustc_hir_typeck/src/closure.rs
+++ b/compiler/rustc_hir_typeck/src/closure.rs
@@ -11,8 +11,8 @@ use rustc_infer::infer::LateBoundRegionConversionTime;
 use rustc_infer::infer::{InferOk, InferResult};
 use rustc_macros::{TypeFoldable, TypeVisitable};
 use rustc_middle::ty::subst::InternalSubsts;
-use rustc_middle::ty::visit::TypeVisitable;
-use rustc_middle::ty::{self, ir::TypeVisitor, Ty, TyCtxt, TypeSuperVisitable};
+use rustc_middle::ty::visit::{TypeVisitable, TypeVisitableExt};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeSuperVisitable, TypeVisitor};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Span;
 use rustc_span::sym;
diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index a15fc9b57fb..706eb3f8647 100644
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -54,7 +54,7 @@ use rustc_middle::ty::adjustment::{
 use rustc_middle::ty::error::TypeError;
 use rustc_middle::ty::relate::RelateResult;
 use rustc_middle::ty::subst::SubstsRef;
-use rustc_middle::ty::visit::TypeVisitable;
+use rustc_middle::ty::visit::TypeVisitableExt;
 use rustc_middle::ty::{self, Ty, TypeAndMut};
 use rustc_session::parse::feature_err;
 use rustc_span::symbol::sym;
diff --git a/compiler/rustc_hir_typeck/src/demand.rs b/compiler/rustc_hir_typeck/src/demand.rs
index 241547b70aa..34d62987c3b 100644
--- a/compiler/rustc_hir_typeck/src/demand.rs
+++ b/compiler/rustc_hir_typeck/src/demand.rs
@@ -16,7 +16,7 @@ use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::fold::{BottomUpFolder, TypeFolder};
 use rustc_middle::ty::print::{with_forced_trimmed_paths, with_no_trimmed_paths};
 use rustc_middle::ty::relate::TypeRelation;
-use rustc_middle::ty::{self, Article, AssocItem, Ty, TypeAndMut, TypeVisitable};
+use rustc_middle::ty::{self, Article, AssocItem, Ty, TypeAndMut, TypeVisitableExt};
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::{BytePos, Span};
 use rustc_trait_selection::infer::InferCtxtExt as _;
diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs
index 08cbfffdd17..4a7bb1b0439 100644
--- a/compiler/rustc_hir_typeck/src/expr.rs
+++ b/compiler/rustc_hir_typeck/src/expr.rs
@@ -42,7 +42,7 @@ use rustc_middle::middle::stability;
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, AllowTwoPhase};
 use rustc_middle::ty::error::TypeError::FieldMisMatch;
 use rustc_middle::ty::subst::SubstsRef;
-use rustc_middle::ty::{self, AdtKind, Ty, TypeVisitable};
+use rustc_middle::ty::{self, AdtKind, Ty, TypeVisitableExt};
 use rustc_session::errors::ExprParenthesesNeeded;
 use rustc_session::parse::feature_err;
 use rustc_span::edit_distance::find_best_match_for_name;
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
index b2f3a3abb4c..67de75301ad 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
@@ -23,9 +23,9 @@ use rustc_infer::infer::InferResult;
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow, AutoBorrowMutability};
 use rustc_middle::ty::error::TypeError;
 use rustc_middle::ty::fold::TypeFoldable;
-use rustc_middle::ty::visit::TypeVisitable;
+use rustc_middle::ty::visit::{TypeVisitable, TypeVisitableExt};
 use rustc_middle::ty::{
-    self, AdtKind, CanonicalUserType, DefIdTree, GenericParamDefKind, Ty, UserType,
+    self, AdtKind, CanonicalUserType, DefIdTree, GenericParamDefKind, Ty, TyCtxt, UserType,
 };
 use rustc_middle::ty::{GenericArgKind, SubstsRef, UserSelfTy, UserSubsts};
 use rustc_session::lint;
@@ -315,7 +315,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
     pub(in super::super) fn normalize<T>(&self, span: Span, value: T) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         self.register_infer_ok_obligations(
             self.at(&self.misc(span), self.param_env).normalize(value),
@@ -443,7 +443,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     // sufficiently enforced with erased regions. =)
     fn can_contain_user_lifetime_bounds<T>(t: T) -> bool
     where
-        T: TypeVisitable<'tcx>,
+        T: TypeVisitable<TyCtxt<'tcx>>,
     {
         t.has_free_regions() || t.has_projections() || t.has_infer_types()
     }
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs
index 39e0ea98f96..d64492e503d 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs
@@ -4,7 +4,7 @@ use rustc_hir::def::Res;
 use rustc_hir::def_id::DefId;
 use rustc_infer::traits::ObligationCauseCode;
 use rustc_middle::ty::{
-    self, ir::TypeVisitor, DefIdTree, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable,
+    self, DefIdTree, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor,
 };
 use rustc_span::{self, Span};
 use rustc_trait_selection::traits;
@@ -243,7 +243,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         true
     }
 
-    fn find_ambiguous_parameter_in<T: TypeVisitable<'tcx>>(
+    fn find_ambiguous_parameter_in<T: TypeVisitable<TyCtxt<'tcx>>>(
         &self,
         item_def_id: DefId,
         t: T,
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index 6a33826ea28..bddf78a5419 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -25,7 +25,7 @@ use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKi
 use rustc_infer::infer::InferOk;
 use rustc_infer::infer::TypeTrace;
 use rustc_middle::ty::adjustment::AllowTwoPhase;
-use rustc_middle::ty::visit::TypeVisitable;
+use rustc_middle::ty::visit::TypeVisitableExt;
 use rustc_middle::ty::{self, DefIdTree, IsSuggestable, Ty};
 use rustc_session::Session;
 use rustc_span::symbol::{kw, Ident};
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
index 3814ddaf73f..1dea3e6f900 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
@@ -18,7 +18,7 @@ use rustc_infer::infer::error_reporting::TypeErrCtxt;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_middle::infer::unify_key::{ConstVariableOrigin, ConstVariableOriginKind};
 use rustc_middle::ty::subst::GenericArgKind;
-use rustc_middle::ty::{self, Const, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, Const, Ty, TyCtxt, TypeVisitableExt};
 use rustc_session::Session;
 use rustc_span::symbol::Ident;
 use rustc_span::{self, Span, DUMMY_SP};
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
index 3f3323cc1af..1c7f131f3d7 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
@@ -17,7 +17,7 @@ use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::{
     self, suggest_constraining_type_params, Binder, DefIdTree, IsSuggestable, ToPredicate, Ty,
-    TypeVisitable,
+    TypeVisitableExt,
 };
 use rustc_session::errors::ExprParenthesesNeeded;
 use rustc_span::source_map::Spanned;
diff --git a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs
index b3dd3031db2..adedb5b7428 100644
--- a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs
+++ b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs
@@ -12,7 +12,7 @@ use rustc_index::vec::IndexVec;
 use rustc_infer::infer::InferCtxt;
 use rustc_middle::{
     hir::map::Map,
-    ty::{ParamEnv, TyCtxt, TypeVisitable, TypeckResults},
+    ty::{ParamEnv, TyCtxt, TypeVisitableExt, TypeckResults},
 };
 use std::mem::swap;
 
diff --git a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/record_consumed_borrow.rs b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/record_consumed_borrow.rs
index ed3d8903157..fa3887362d9 100644
--- a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/record_consumed_borrow.rs
+++ b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/record_consumed_borrow.rs
@@ -9,7 +9,7 @@ use rustc_hir as hir;
 use rustc_middle::ty::{ParamEnv, TyCtxt};
 use rustc_middle::{
     hir::place::{PlaceBase, Projection, ProjectionKind},
-    ty::TypeVisitable,
+    ty::TypeVisitableExt,
 };
 
 pub(super) fn find_consumed_and_borrowed<'a, 'tcx>(
diff --git a/compiler/rustc_hir_typeck/src/generator_interior/mod.rs b/compiler/rustc_hir_typeck/src/generator_interior/mod.rs
index 14e3ba83b10..e5f9292290f 100644
--- a/compiler/rustc_hir_typeck/src/generator_interior/mod.rs
+++ b/compiler/rustc_hir_typeck/src/generator_interior/mod.rs
@@ -16,7 +16,7 @@ use rustc_hir::{Arm, Expr, ExprKind, Guard, HirId, Pat, PatKind};
 use rustc_infer::infer::RegionVariableOrigin;
 use rustc_middle::middle::region::{self, Scope, ScopeData, YieldData};
 use rustc_middle::ty::fold::FnMutDelegate;
-use rustc_middle::ty::{self, BoundVariableKind, RvalueScopes, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, BoundVariableKind, RvalueScopes, Ty, TyCtxt, TypeVisitableExt};
 use rustc_span::symbol::sym;
 use rustc_span::Span;
 use smallvec::{smallvec, SmallVec};
diff --git a/compiler/rustc_hir_typeck/src/inherited.rs b/compiler/rustc_hir_typeck/src/inherited.rs
index 87e54025330..26020382d81 100644
--- a/compiler/rustc_hir_typeck/src/inherited.rs
+++ b/compiler/rustc_hir_typeck/src/inherited.rs
@@ -6,7 +6,7 @@ use rustc_hir::def_id::LocalDefId;
 use rustc_hir::HirIdMap;
 use rustc_infer::infer;
 use rustc_infer::infer::{DefiningAnchor, InferCtxt, InferOk, TyCtxtInferExt};
-use rustc_middle::ty::visit::TypeVisitable;
+use rustc_middle::ty::visit::TypeVisitableExt;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::def_id::LocalDefIdMap;
 use rustc_span::{self, Span};
diff --git a/compiler/rustc_hir_typeck/src/intrinsicck.rs b/compiler/rustc_hir_typeck/src/intrinsicck.rs
index 2c76582f2ec..19d2befc438 100644
--- a/compiler/rustc_hir_typeck/src/intrinsicck.rs
+++ b/compiler/rustc_hir_typeck/src/intrinsicck.rs
@@ -3,7 +3,7 @@ use rustc_errors::struct_span_err;
 use rustc_hir as hir;
 use rustc_index::vec::Idx;
 use rustc_middle::ty::layout::{LayoutError, SizeSkeleton};
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
 use rustc_target::abi::{Pointer, VariantIdx};
 
 use super::FnCtxt;
diff --git a/compiler/rustc_hir_typeck/src/mem_categorization.rs b/compiler/rustc_hir_typeck/src/mem_categorization.rs
index 4b08832eddc..e50f5c77552 100644
--- a/compiler/rustc_hir_typeck/src/mem_categorization.rs
+++ b/compiler/rustc_hir_typeck/src/mem_categorization.rs
@@ -51,7 +51,7 @@
 use rustc_middle::hir::place::*;
 use rustc_middle::ty::adjustment;
 use rustc_middle::ty::fold::TypeFoldable;
-use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
 
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_hir as hir;
@@ -126,7 +126,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> {
 
     fn resolve_vars_if_possible<T>(&self, value: T) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         self.infcx.resolve_vars_if_possible(value)
     }
diff --git a/compiler/rustc_hir_typeck/src/method/confirm.rs b/compiler/rustc_hir_typeck/src/method/confirm.rs
index f7de55c989f..169f128e0a0 100644
--- a/compiler/rustc_hir_typeck/src/method/confirm.rs
+++ b/compiler/rustc_hir_typeck/src/method/confirm.rs
@@ -14,7 +14,7 @@ use rustc_middle::ty::adjustment::{Adjust, Adjustment, PointerCast};
 use rustc_middle::ty::adjustment::{AllowTwoPhase, AutoBorrow, AutoBorrowMutability};
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::subst::{self, SubstsRef};
-use rustc_middle::ty::{self, GenericParamDefKind, Ty};
+use rustc_middle::ty::{self, GenericParamDefKind, Ty, TyCtxt};
 use rustc_middle::ty::{InternalSubsts, UserSubsts, UserType};
 use rustc_span::{Span, DUMMY_SP};
 use rustc_trait_selection::traits;
@@ -635,7 +635,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
 
     fn instantiate_binder_with_fresh_vars<T>(&self, value: ty::Binder<'tcx, T>) -> T
     where
-        T: TypeFoldable<'tcx> + Copy,
+        T: TypeFoldable<TyCtxt<'tcx>> + Copy,
     {
         self.fcx.instantiate_binder_with_fresh_vars(self.span, infer::FnCall, value)
     }
diff --git a/compiler/rustc_hir_typeck/src/method/mod.rs b/compiler/rustc_hir_typeck/src/method/mod.rs
index c9ae82e8efb..0456dd56c34 100644
--- a/compiler/rustc_hir_typeck/src/method/mod.rs
+++ b/compiler/rustc_hir_typeck/src/method/mod.rs
@@ -20,7 +20,7 @@ use rustc_hir::def_id::DefId;
 use rustc_infer::infer::{self, InferOk};
 use rustc_middle::traits::ObligationCause;
 use rustc_middle::ty::subst::{InternalSubsts, SubstsRef};
-use rustc_middle::ty::{self, GenericParamDefKind, Ty, TypeVisitable};
+use rustc_middle::ty::{self, GenericParamDefKind, Ty, TypeVisitableExt};
 use rustc_span::symbol::Ident;
 use rustc_span::Span;
 use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt;
diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
index 8b0473b7454..fc876802a4b 100644
--- a/compiler/rustc_hir_typeck/src/method/probe.rs
+++ b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -19,7 +19,7 @@ use rustc_middle::ty::fast_reject::{simplify_type, TreatParams};
 use rustc_middle::ty::AssocItem;
 use rustc_middle::ty::GenericParamDefKind;
 use rustc_middle::ty::ToPredicate;
-use rustc_middle::ty::{self, ParamEnvAnd, Ty, TyCtxt, TypeFoldable};
+use rustc_middle::ty::{self, ParamEnvAnd, Ty, TyCtxt, TypeFoldable, TypeVisitableExt};
 use rustc_middle::ty::{InternalSubsts, SubstsRef};
 use rustc_session::lint;
 use rustc_span::def_id::DefId;
@@ -1905,7 +1905,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
     ///    so forth.
     fn erase_late_bound_regions<T>(&self, value: ty::Binder<'tcx, T>) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         self.tcx.erase_late_bound_regions(value)
     }
diff --git a/compiler/rustc_hir_typeck/src/method/suggest.rs b/compiler/rustc_hir_typeck/src/method/suggest.rs
index 4f3dbe03c05..f3f15ee0ae4 100644
--- a/compiler/rustc_hir_typeck/src/method/suggest.rs
+++ b/compiler/rustc_hir_typeck/src/method/suggest.rs
@@ -27,7 +27,7 @@ use rustc_middle::traits::util::supertraits;
 use rustc_middle::ty::fast_reject::DeepRejectCtxt;
 use rustc_middle::ty::fast_reject::{simplify_type, TreatParams};
 use rustc_middle::ty::print::{with_crate_prefix, with_forced_trimmed_paths};
-use rustc_middle::ty::{self, DefIdTree, GenericArgKind, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, DefIdTree, GenericArgKind, Ty, TyCtxt, TypeVisitableExt};
 use rustc_middle::ty::{IsSuggestable, ToPolyTraitRef};
 use rustc_span::symbol::{kw, sym, Ident};
 use rustc_span::Symbol;
diff --git a/compiler/rustc_hir_typeck/src/op.rs b/compiler/rustc_hir_typeck/src/op.rs
index c8256e7ec08..bb9d93d5057 100644
--- a/compiler/rustc_hir_typeck/src/op.rs
+++ b/compiler/rustc_hir_typeck/src/op.rs
@@ -13,7 +13,7 @@ use rustc_middle::ty::adjustment::{
 };
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::{
-    self, ir::TypeFolder, DefIdTree, IsSuggestable, Ty, TyCtxt, TypeSuperFoldable, TypeVisitable,
+    self, DefIdTree, IsSuggestable, Ty, TyCtxt, TypeFolder, TypeSuperFoldable, TypeVisitableExt,
 };
 use rustc_session::errors::ExprParenthesesNeeded;
 use rustc_span::source_map::Spanned;
diff --git a/compiler/rustc_hir_typeck/src/pat.rs b/compiler/rustc_hir_typeck/src/pat.rs
index ab6e76ef8aa..b739324099d 100644
--- a/compiler/rustc_hir_typeck/src/pat.rs
+++ b/compiler/rustc_hir_typeck/src/pat.rs
@@ -12,7 +12,7 @@ use rustc_hir::{HirId, Pat, PatKind};
 use rustc_infer::infer;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_middle::middle::stability::EvalResult;
-use rustc_middle::ty::{self, Adt, BindingMode, Ty, TypeVisitable};
+use rustc_middle::ty::{self, Adt, BindingMode, Ty, TypeVisitableExt};
 use rustc_session::lint::builtin::NON_EXHAUSTIVE_OMITTED_PATTERNS;
 use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::hygiene::DesugaringKind;
diff --git a/compiler/rustc_hir_typeck/src/writeback.rs b/compiler/rustc_hir_typeck/src/writeback.rs
index b6c9a88c82d..0394567cb09 100644
--- a/compiler/rustc_hir_typeck/src/writeback.rs
+++ b/compiler/rustc_hir_typeck/src/writeback.rs
@@ -13,8 +13,8 @@ use rustc_infer::infer::InferCtxt;
 use rustc_middle::hir::place::Place as HirPlace;
 use rustc_middle::mir::FakeReadCause;
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, PointerCast};
-use rustc_middle::ty::fold::{ir::TypeFolder, TypeFoldable, TypeSuperFoldable};
-use rustc_middle::ty::visit::TypeSuperVisitable;
+use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
+use rustc_middle::ty::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitableExt};
 use rustc_middle::ty::TypeckResults;
 use rustc_middle::ty::{self, ClosureSizeProfileData, Ty, TyCtxt};
 use rustc_span::symbol::sym;
@@ -561,7 +561,7 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
             struct RecursionChecker {
                 def_id: LocalDefId,
             }
-            impl<'tcx> ty::ir::TypeVisitor<TyCtxt<'tcx>> for RecursionChecker {
+            impl<'tcx> ty::TypeVisitor<TyCtxt<'tcx>> for RecursionChecker {
                 type BreakTy = ();
                 fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
                     if let ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }) = *t.kind() {
@@ -685,7 +685,7 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
 
     fn resolve<T>(&mut self, x: T, span: &dyn Locatable) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         let mut resolver = Resolver::new(self.fcx, span, self.body);
         let x = x.fold_with(&mut resolver);
diff --git a/compiler/rustc_infer/src/infer/canonical/canonicalizer.rs b/compiler/rustc_infer/src/infer/canonical/canonicalizer.rs
index b736a416e4a..f66f6bd4ae1 100644
--- a/compiler/rustc_infer/src/infer/canonical/canonicalizer.rs
+++ b/compiler/rustc_infer/src/infer/canonical/canonicalizer.rs
@@ -10,9 +10,9 @@ use crate::infer::canonical::{
 };
 use crate::infer::InferCtxt;
 use rustc_middle::ty::flags::FlagComputation;
-use rustc_middle::ty::fold::{ir::TypeFolder, TypeFoldable, TypeSuperFoldable};
+use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
 use rustc_middle::ty::subst::GenericArg;
-use rustc_middle::ty::{self, BoundVar, InferConst, List, Ty, TyCtxt, TypeFlags};
+use rustc_middle::ty::{self, BoundVar, InferConst, List, Ty, TyCtxt, TypeFlags, TypeVisitableExt};
 use std::sync::atomic::Ordering;
 
 use rustc_data_structures::fx::FxHashMap;
@@ -41,7 +41,7 @@ impl<'tcx> InferCtxt<'tcx> {
         query_state: &mut OriginalQueryValues<'tcx>,
     ) -> Canonical<'tcx, V>
     where
-        V: TypeFoldable<'tcx>,
+        V: TypeFoldable<TyCtxt<'tcx>>,
     {
         self.tcx.sess.perf_stats.queries_canonicalized.fetch_add(1, Ordering::Relaxed);
 
@@ -60,7 +60,7 @@ impl<'tcx> InferCtxt<'tcx> {
         query_state: &mut OriginalQueryValues<'tcx>,
     ) -> Canonical<'tcx, V>
     where
-        V: TypeFoldable<'tcx>,
+        V: TypeFoldable<TyCtxt<'tcx>>,
     {
         self.tcx.sess.perf_stats.queries_canonicalized.fetch_add(1, Ordering::Relaxed);
 
@@ -100,7 +100,7 @@ impl<'tcx> InferCtxt<'tcx> {
     /// [c]: https://rust-lang.github.io/chalk/book/canonical_queries/canonicalization.html#canonicalizing-the-query-result
     pub fn canonicalize_response<V>(&self, value: V) -> Canonical<'tcx, V>
     where
-        V: TypeFoldable<'tcx>,
+        V: TypeFoldable<TyCtxt<'tcx>>,
     {
         let mut query_state = OriginalQueryValues::default();
         Canonicalizer::canonicalize(
@@ -114,7 +114,7 @@ impl<'tcx> InferCtxt<'tcx> {
 
     pub fn canonicalize_user_type_annotation<V>(&self, value: V) -> Canonical<'tcx, V>
     where
-        V: TypeFoldable<'tcx>,
+        V: TypeFoldable<TyCtxt<'tcx>>,
     {
         let mut query_state = OriginalQueryValues::default();
         Canonicalizer::canonicalize(
@@ -136,7 +136,7 @@ impl<'tcx> InferCtxt<'tcx> {
         query_state: &mut OriginalQueryValues<'tcx>,
     ) -> Canonical<'tcx, V>
     where
-        V: TypeFoldable<'tcx>,
+        V: TypeFoldable<TyCtxt<'tcx>>,
     {
         self.tcx.sess.perf_stats.queries_canonicalized.fetch_add(1, Ordering::Relaxed);
 
@@ -333,7 +333,7 @@ impl<'cx, 'tcx> TypeFolder<TyCtxt<'tcx>> for Canonicalizer<'cx, 'tcx> {
 
     fn fold_binder<T>(&mut self, t: ty::Binder<'tcx, T>) -> ty::Binder<'tcx, T>
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         self.binder_index.shift_in(1);
         let t = t.super_fold_with(self);
@@ -530,7 +530,7 @@ impl<'cx, 'tcx> Canonicalizer<'cx, 'tcx> {
         query_state: &mut OriginalQueryValues<'tcx>,
     ) -> Canonical<'tcx, V>
     where
-        V: TypeFoldable<'tcx>,
+        V: TypeFoldable<TyCtxt<'tcx>>,
     {
         let needs_canonical_flags = if canonicalize_region_mode.any() {
             TypeFlags::NEEDS_INFER |
diff --git a/compiler/rustc_infer/src/infer/canonical/mod.rs b/compiler/rustc_infer/src/infer/canonical/mod.rs
index 4552256545b..4053546f00c 100644
--- a/compiler/rustc_infer/src/infer/canonical/mod.rs
+++ b/compiler/rustc_infer/src/infer/canonical/mod.rs
@@ -26,7 +26,7 @@ use crate::infer::{InferCtxt, RegionVariableOrigin, TypeVariableOrigin, TypeVari
 use rustc_index::vec::IndexVec;
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::subst::GenericArg;
-use rustc_middle::ty::{self, List};
+use rustc_middle::ty::{self, List, TyCtxt};
 use rustc_span::source_map::Span;
 
 pub use rustc_middle::infer::canonical::*;
@@ -55,7 +55,7 @@ impl<'tcx> InferCtxt<'tcx> {
         canonical: &Canonical<'tcx, T>,
     ) -> (T, CanonicalVarValues<'tcx>)
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         // For each universe that is referred to in the incoming
         // query, create a universe in our local inference context. In
diff --git a/compiler/rustc_infer/src/infer/canonical/query_response.rs b/compiler/rustc_infer/src/infer/canonical/query_response.rs
index e993fb4c22b..d3470d70f65 100644
--- a/compiler/rustc_infer/src/infer/canonical/query_response.rs
+++ b/compiler/rustc_infer/src/infer/canonical/query_response.rs
@@ -59,7 +59,7 @@ impl<'tcx> InferCtxt<'tcx> {
         fulfill_cx: &mut dyn TraitEngine<'tcx>,
     ) -> Fallible<CanonicalQueryResponse<'tcx, T>>
     where
-        T: Debug + TypeFoldable<'tcx>,
+        T: Debug + TypeFoldable<TyCtxt<'tcx>>,
         Canonical<'tcx, QueryResponse<'tcx, T>>: ArenaAllocatable<'tcx>,
     {
         let query_response = self.make_query_response(inference_vars, answer, fulfill_cx)?;
@@ -85,7 +85,7 @@ impl<'tcx> InferCtxt<'tcx> {
         answer: T,
     ) -> Canonical<'tcx, QueryResponse<'tcx, T>>
     where
-        T: Debug + TypeFoldable<'tcx>,
+        T: Debug + TypeFoldable<TyCtxt<'tcx>>,
     {
         self.canonicalize_response(QueryResponse {
             var_values: inference_vars,
@@ -106,7 +106,7 @@ impl<'tcx> InferCtxt<'tcx> {
         fulfill_cx: &mut dyn TraitEngine<'tcx>,
     ) -> Result<QueryResponse<'tcx, T>, NoSolution>
     where
-        T: Debug + TypeFoldable<'tcx>,
+        T: Debug + TypeFoldable<TyCtxt<'tcx>>,
     {
         let tcx = self.tcx;
 
@@ -180,7 +180,7 @@ impl<'tcx> InferCtxt<'tcx> {
         query_response: &Canonical<'tcx, QueryResponse<'tcx, R>>,
     ) -> InferResult<'tcx, R>
     where
-        R: Debug + TypeFoldable<'tcx>,
+        R: Debug + TypeFoldable<TyCtxt<'tcx>>,
     {
         let InferOk { value: result_subst, mut obligations } =
             self.query_response_substitution(cause, param_env, original_values, query_response)?;
@@ -242,7 +242,7 @@ impl<'tcx> InferCtxt<'tcx> {
         output_query_region_constraints: &mut QueryRegionConstraints<'tcx>,
     ) -> InferResult<'tcx, R>
     where
-        R: Debug + TypeFoldable<'tcx>,
+        R: Debug + TypeFoldable<TyCtxt<'tcx>>,
     {
         let InferOk { value: result_subst, mut obligations } = self
             .query_response_substitution_guess(cause, param_env, original_values, query_response)?;
@@ -356,7 +356,7 @@ impl<'tcx> InferCtxt<'tcx> {
         query_response: &Canonical<'tcx, QueryResponse<'tcx, R>>,
     ) -> InferResult<'tcx, CanonicalVarValues<'tcx>>
     where
-        R: Debug + TypeFoldable<'tcx>,
+        R: Debug + TypeFoldable<TyCtxt<'tcx>>,
     {
         debug!(
             "query_response_substitution(original_values={:#?}, query_response={:#?})",
@@ -401,7 +401,7 @@ impl<'tcx> InferCtxt<'tcx> {
         query_response: &Canonical<'tcx, QueryResponse<'tcx, R>>,
     ) -> InferResult<'tcx, CanonicalVarValues<'tcx>>
     where
-        R: Debug + TypeFoldable<'tcx>,
+        R: Debug + TypeFoldable<TyCtxt<'tcx>>,
     {
         debug!(
             "query_response_substitution_guess(original_values={:#?}, query_response={:#?})",
@@ -523,7 +523,7 @@ impl<'tcx> InferCtxt<'tcx> {
         query_response: &Canonical<'tcx, QueryResponse<'tcx, R>>,
     ) -> InferResult<'tcx, ()>
     where
-        R: Debug + TypeFoldable<'tcx>,
+        R: Debug + TypeFoldable<TyCtxt<'tcx>>,
     {
         // A closure that yields the result value for the given
         // canonical variable; this is taken from
diff --git a/compiler/rustc_infer/src/infer/canonical/substitute.rs b/compiler/rustc_infer/src/infer/canonical/substitute.rs
index e77f2d37b7d..c5c6fc41b9e 100644
--- a/compiler/rustc_infer/src/infer/canonical/substitute.rs
+++ b/compiler/rustc_infer/src/infer/canonical/substitute.rs
@@ -16,7 +16,7 @@ pub(super) trait CanonicalExt<'tcx, V> {
     /// with the value given in `var_values`.
     fn substitute(&self, tcx: TyCtxt<'tcx>, var_values: &CanonicalVarValues<'tcx>) -> V
     where
-        V: TypeFoldable<'tcx>;
+        V: TypeFoldable<TyCtxt<'tcx>>;
 
     /// Allows one to apply a substitute to some subset of
     /// `self.value`. Invoke `projection_fn` with `self.value` to get
@@ -31,13 +31,13 @@ pub(super) trait CanonicalExt<'tcx, V> {
         projection_fn: impl FnOnce(&V) -> T,
     ) -> T
     where
-        T: TypeFoldable<'tcx>;
+        T: TypeFoldable<TyCtxt<'tcx>>;
 }
 
 impl<'tcx, V> CanonicalExt<'tcx, V> for Canonical<'tcx, V> {
     fn substitute(&self, tcx: TyCtxt<'tcx>, var_values: &CanonicalVarValues<'tcx>) -> V
     where
-        V: TypeFoldable<'tcx>,
+        V: TypeFoldable<TyCtxt<'tcx>>,
     {
         self.substitute_projected(tcx, var_values, |value| value.clone())
     }
@@ -49,7 +49,7 @@ impl<'tcx, V> CanonicalExt<'tcx, V> for Canonical<'tcx, V> {
         projection_fn: impl FnOnce(&V) -> T,
     ) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         assert_eq!(self.variables.len(), var_values.len());
         let value = projection_fn(&self.value);
@@ -66,7 +66,7 @@ pub(super) fn substitute_value<'tcx, T>(
     value: T,
 ) -> T
 where
-    T: TypeFoldable<'tcx>,
+    T: TypeFoldable<TyCtxt<'tcx>>,
 {
     if var_values.var_values.is_empty() {
         value
diff --git a/compiler/rustc_infer/src/infer/combine.rs b/compiler/rustc_infer/src/infer/combine.rs
index f5504b05dc4..243545640f9 100644
--- a/compiler/rustc_infer/src/infer/combine.rs
+++ b/compiler/rustc_infer/src/infer/combine.rs
@@ -40,8 +40,8 @@ use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::relate::{self, Relate, RelateResult, TypeRelation};
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{
-    self, ir::FallibleTypeFolder, AliasKind, InferConst, ToPredicate, Ty, TyCtxt, TypeFoldable,
-    TypeSuperFoldable,
+    self, AliasKind, FallibleTypeFolder, InferConst, ToPredicate, Ty, TyCtxt, TypeFoldable,
+    TypeSuperFoldable, TypeVisitableExt,
 };
 use rustc_middle::ty::{IntType, UintType};
 use rustc_span::{Span, DUMMY_SP};
diff --git a/compiler/rustc_infer/src/infer/equate.rs b/compiler/rustc_infer/src/infer/equate.rs
index 742c01efff6..f830e9b3c53 100644
--- a/compiler/rustc_infer/src/infer/equate.rs
+++ b/compiler/rustc_infer/src/infer/equate.rs
@@ -6,7 +6,7 @@ use super::Subtype;
 use rustc_middle::ty::relate::{self, Relate, RelateResult, TypeRelation};
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::TyVar;
-use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
 
 use rustc_hir::def_id::DefId;
 
diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index dd6a76f754d..95635405f89 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -72,7 +72,7 @@ use rustc_middle::ty::print::with_forced_trimmed_paths;
 use rustc_middle::ty::relate::{self, RelateResult, TypeRelation};
 use rustc_middle::ty::{
     self, error::TypeError, List, Region, Ty, TyCtxt, TypeFoldable, TypeSuperVisitable,
-    TypeVisitable,
+    TypeVisitable, TypeVisitableExt,
 };
 use rustc_span::{sym, symbol::kw, BytePos, DesugaringKind, Pos, Span};
 use rustc_target::spec::abi;
@@ -1450,8 +1450,8 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
         impl<'tcx> OpaqueTypesVisitor<'tcx> {
             fn visit_expected_found(
                 tcx: TyCtxt<'tcx>,
-                expected: impl TypeVisitable<'tcx>,
-                found: impl TypeVisitable<'tcx>,
+                expected: impl TypeVisitable<TyCtxt<'tcx>>,
+                found: impl TypeVisitable<TyCtxt<'tcx>>,
                 ignore_span: Span,
             ) -> Self {
                 let mut types_visitor = OpaqueTypesVisitor {
@@ -1501,7 +1501,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             }
         }
 
-        impl<'tcx> ty::visit::ir::TypeVisitor<TyCtxt<'tcx>> for OpaqueTypesVisitor<'tcx> {
+        impl<'tcx> ty::visit::TypeVisitor<TyCtxt<'tcx>> for OpaqueTypesVisitor<'tcx> {
             fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
                 if let Some((kind, def_id)) = TyCategory::from_ty(self.tcx, t) {
                     let span = self.tcx.def_span(def_id);
@@ -2206,7 +2206,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
     }
 
     /// Returns a string of the form "expected `{}`, found `{}`".
-    fn expected_found_str<T: fmt::Display + TypeFoldable<'tcx>>(
+    fn expected_found_str<T: fmt::Display + TypeFoldable<TyCtxt<'tcx>>>(
         &self,
         exp_found: ty::error::ExpectedFound<T>,
     ) -> Option<(DiagnosticStyledString, DiagnosticStyledString, Option<PathBuf>, Option<PathBuf>)>
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
index 641477e907d..b06ff10d86e 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
@@ -17,8 +17,7 @@ use rustc_hir::{
     TyKind,
 };
 use rustc_middle::ty::{
-    self, ir::TypeVisitor, AssocItemContainer, StaticLifetimeVisitor, Ty, TyCtxt,
-    TypeSuperVisitable,
+    self, AssocItemContainer, StaticLifetimeVisitor, Ty, TyCtxt, TypeSuperVisitable, TypeVisitor,
 };
 use rustc_span::symbol::Ident;
 use rustc_span::Span;
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/trait_impl_difference.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/trait_impl_difference.rs
index d295881d5d7..2875448ee15 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/trait_impl_difference.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/trait_impl_difference.rs
@@ -75,7 +75,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
             }
         }
 
-        impl<'tcx> ty::visit::ir::TypeVisitor<TyCtxt<'tcx>> for HighlightBuilder<'tcx> {
+        impl<'tcx> ty::visit::TypeVisitor<TyCtxt<'tcx>> for HighlightBuilder<'tcx> {
             fn visit_region(&mut self, r: ty::Region<'tcx>) -> ControlFlow<Self::BreakTy> {
                 if !r.has_name() && self.counter <= 3 {
                     self.highlight.highlighting_region(r, self.counter);
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs
index ac4de2cc842..db4b8af4683 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/util.rs
@@ -143,7 +143,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
 
     fn includes_region(
         &self,
-        ty: Binder<'tcx, impl TypeVisitable<'tcx>>,
+        ty: Binder<'tcx, impl TypeVisitable<TyCtxt<'tcx>>>,
         region: ty::BoundRegionKind,
     ) -> bool {
         let late_bound_regions = self.tcx().collect_referenced_late_bound_regions(&ty);
diff --git a/compiler/rustc_infer/src/infer/error_reporting/suggest.rs b/compiler/rustc_infer/src/infer/error_reporting/suggest.rs
index 18c5097a262..55dcfd05e0a 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/suggest.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/suggest.rs
@@ -8,7 +8,7 @@ use rustc_middle::traits::{
     StatementAsExpression,
 };
 use rustc_middle::ty::print::with_no_trimmed_paths;
-use rustc_middle::ty::{self as ty, IsSuggestable, Ty, TypeVisitable};
+use rustc_middle::ty::{self as ty, IsSuggestable, Ty, TypeVisitableExt};
 use rustc_span::{sym, BytePos, Span};
 
 use crate::errors::{
diff --git a/compiler/rustc_infer/src/infer/freshen.rs b/compiler/rustc_infer/src/infer/freshen.rs
index 41bffdc684d..f09f93abf45 100644
--- a/compiler/rustc_infer/src/infer/freshen.rs
+++ b/compiler/rustc_infer/src/infer/freshen.rs
@@ -33,8 +33,8 @@
 use super::InferCtxt;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_middle::infer::unify_key::ToType;
-use rustc_middle::ty::fold::ir::TypeFolder;
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable};
+use rustc_middle::ty::fold::TypeFolder;
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable, TypeVisitableExt};
 use std::collections::hash_map::Entry;
 
 pub struct TypeFreshener<'a, 'tcx> {
diff --git a/compiler/rustc_infer/src/infer/fudge.rs b/compiler/rustc_infer/src/infer/fudge.rs
index cc2f19a5704..86c2c2be4a8 100644
--- a/compiler/rustc_infer/src/infer/fudge.rs
+++ b/compiler/rustc_infer/src/infer/fudge.rs
@@ -1,4 +1,4 @@
-use rustc_middle::ty::fold::{ir::TypeFolder, TypeFoldable, TypeSuperFoldable};
+use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
 use rustc_middle::ty::{self, ConstVid, FloatVid, IntVid, RegionVid, Ty, TyCtxt, TyVid};
 
 use super::type_variable::TypeVariableOrigin;
@@ -98,7 +98,7 @@ impl<'tcx> InferCtxt<'tcx> {
     pub fn fudge_inference_if_ok<T, E, F>(&self, f: F) -> Result<T, E>
     where
         F: FnOnce() -> Result<T, E>,
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         let variable_lengths = self.variable_lengths();
         let (mut fudger, value) = self.probe(|_| {
diff --git a/compiler/rustc_infer/src/infer/glb.rs b/compiler/rustc_infer/src/infer/glb.rs
index 74abca7bbea..37ef022f827 100644
--- a/compiler/rustc_infer/src/infer/glb.rs
+++ b/compiler/rustc_infer/src/infer/glb.rs
@@ -7,7 +7,7 @@ use super::Subtype;
 
 use crate::traits::{ObligationCause, PredicateObligations};
 use rustc_middle::ty::relate::{Relate, RelateResult, TypeRelation};
-use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
 
 /// "Greatest lower bound" (common subtype)
 pub struct Glb<'combine, 'infcx, 'tcx> {
diff --git a/compiler/rustc_infer/src/infer/higher_ranked/mod.rs b/compiler/rustc_infer/src/infer/higher_ranked/mod.rs
index 82a1bb1fd16..d1897cf24b4 100644
--- a/compiler/rustc_infer/src/infer/higher_ranked/mod.rs
+++ b/compiler/rustc_infer/src/infer/higher_ranked/mod.rs
@@ -6,7 +6,7 @@ use super::{HigherRankedType, InferCtxt};
 use crate::infer::CombinedSnapshot;
 use rustc_middle::ty::fold::FnMutDelegate;
 use rustc_middle::ty::relate::{Relate, RelateResult, TypeRelation};
-use rustc_middle::ty::{self, Binder, TypeFoldable};
+use rustc_middle::ty::{self, Binder, TyCtxt, TypeFoldable};
 
 impl<'a, 'tcx> CombineFields<'a, 'tcx> {
     /// Checks whether `for<..> sub <: for<..> sup` holds.
@@ -72,7 +72,7 @@ impl<'tcx> InferCtxt<'tcx> {
     #[instrument(level = "debug", skip(self), ret)]
     pub fn instantiate_binder_with_placeholders<T>(&self, binder: ty::Binder<'tcx, T>) -> T
     where
-        T: TypeFoldable<'tcx> + Copy,
+        T: TypeFoldable<TyCtxt<'tcx>> + Copy,
     {
         if let Some(inner) = binder.no_bound_vars() {
             return inner;
diff --git a/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs b/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs
index ac203c4eb0b..175d02bc3cd 100644
--- a/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs
+++ b/compiler/rustc_infer/src/infer/lexical_region_resolve/mod.rs
@@ -1024,7 +1024,7 @@ impl<'tcx> fmt::Debug for RegionAndOrigin<'tcx> {
 impl<'tcx> LexicalRegionResolutions<'tcx> {
     fn normalize<T>(&self, tcx: TyCtxt<'tcx>, value: T) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         tcx.fold_regions(value, |r, _db| self.resolve_region(tcx, r))
     }
diff --git a/compiler/rustc_infer/src/infer/lub.rs b/compiler/rustc_infer/src/infer/lub.rs
index f997171b97f..f541fcbceed 100644
--- a/compiler/rustc_infer/src/infer/lub.rs
+++ b/compiler/rustc_infer/src/infer/lub.rs
@@ -7,7 +7,7 @@ use super::Subtype;
 
 use crate::traits::{ObligationCause, PredicateObligations};
 use rustc_middle::ty::relate::{Relate, RelateResult, TypeRelation};
-use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
 
 /// "Least upper bound" (common supertype)
 pub struct Lub<'combine, 'infcx, 'tcx> {
diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs
index 29c9af5c43f..cf8007c964d 100644
--- a/compiler/rustc_infer/src/infer/mod.rs
+++ b/compiler/rustc_infer/src/infer/mod.rs
@@ -26,10 +26,10 @@ use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::traits::select;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::fold::BoundVarReplacerDelegate;
-use rustc_middle::ty::fold::{ir::TypeFolder, TypeFoldable, TypeSuperFoldable};
+use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
 use rustc_middle::ty::relate::RelateResult;
 use rustc_middle::ty::subst::{GenericArg, GenericArgKind, InternalSubsts, SubstsRef};
-use rustc_middle::ty::visit::TypeVisitable;
+use rustc_middle::ty::visit::{TypeVisitable, TypeVisitableExt};
 pub use rustc_middle::ty::IntVarValue;
 use rustc_middle::ty::{self, GenericParamDefKind, InferConst, InferTy, Ty, TyCtxt};
 use rustc_middle::ty::{ConstVid, FloatVid, IntVid, TyVid};
@@ -617,7 +617,7 @@ impl<'tcx> InferCtxtBuilder<'tcx> {
         canonical: &Canonical<'tcx, T>,
     ) -> (InferCtxt<'tcx>, T, CanonicalVarValues<'tcx>)
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         let infcx = self.build();
         let (value, subst) = infcx.instantiate_canonical_with_fresh_inference_vars(span, canonical);
@@ -697,7 +697,7 @@ impl<'tcx> InferCtxt<'tcx> {
         self.in_snapshot.get()
     }
 
-    pub fn freshen<T: TypeFoldable<'tcx>>(&self, t: T) -> T {
+    pub fn freshen<T: TypeFoldable<TyCtxt<'tcx>>>(&self, t: T) -> T {
         t.fold_with(&mut self.freshener())
     }
 
@@ -1371,7 +1371,7 @@ impl<'tcx> InferCtxt<'tcx> {
     /// will be resolving them as well, e.g. in a loop).
     pub fn shallow_resolve<T>(&self, value: T) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         value.fold_with(&mut ShallowResolver { infcx: self })
     }
@@ -1388,7 +1388,7 @@ impl<'tcx> InferCtxt<'tcx> {
     /// at will.
     pub fn resolve_vars_if_possible<T>(&self, value: T) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         if !value.has_non_region_infer() {
             return value;
@@ -1399,7 +1399,7 @@ impl<'tcx> InferCtxt<'tcx> {
 
     pub fn resolve_numeric_literals_with_default<T>(&self, value: T) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         if !value.needs_infer() {
             return value; // Avoid duplicated subst-folding.
@@ -1414,7 +1414,7 @@ impl<'tcx> InferCtxt<'tcx> {
         value: &T,
     ) -> Option<(ty::Term<'tcx>, Option<Span>)>
     where
-        T: TypeVisitable<'tcx>,
+        T: TypeVisitable<TyCtxt<'tcx>>,
     {
         value.visit_with(&mut resolve::UnresolvedTypeOrConstFinder::new(self)).break_value()
     }
@@ -1429,7 +1429,7 @@ impl<'tcx> InferCtxt<'tcx> {
         }
     }
 
-    pub fn fully_resolve<T: TypeFoldable<'tcx>>(&self, value: T) -> FixupResult<'tcx, T> {
+    pub fn fully_resolve<T: TypeFoldable<TyCtxt<'tcx>>>(&self, value: T) -> FixupResult<'tcx, T> {
         /*!
          * Attempts to resolve all type/region/const variables in
          * `value`. Region inference must have been run already (e.g.,
@@ -1462,7 +1462,7 @@ impl<'tcx> InferCtxt<'tcx> {
         value: ty::Binder<'tcx, T>,
     ) -> T
     where
-        T: TypeFoldable<'tcx> + Copy,
+        T: TypeFoldable<TyCtxt<'tcx>> + Copy,
     {
         if let Some(inner) = value.no_bound_vars() {
             return inner;
diff --git a/compiler/rustc_infer/src/infer/nll_relate/mod.rs b/compiler/rustc_infer/src/infer/nll_relate/mod.rs
index 954334e88b0..214a5850fb6 100644
--- a/compiler/rustc_infer/src/infer/nll_relate/mod.rs
+++ b/compiler/rustc_infer/src/infer/nll_relate/mod.rs
@@ -29,7 +29,7 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_middle::traits::ObligationCause;
 use rustc_middle::ty::error::TypeError;
 use rustc_middle::ty::relate::{self, Relate, RelateResult, TypeRelation};
-use rustc_middle::ty::visit::{ir::TypeVisitor, TypeSuperVisitable, TypeVisitable};
+use rustc_middle::ty::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor};
 use rustc_middle::ty::{self, InferConst, Ty, TyCtxt};
 use rustc_span::{Span, Symbol};
 use std::fmt::Debug;
@@ -797,7 +797,7 @@ struct ScopeInstantiator<'me, 'tcx> {
 }
 
 impl<'me, 'tcx> TypeVisitor<TyCtxt<'tcx>> for ScopeInstantiator<'me, 'tcx> {
-    fn visit_binder<T: TypeVisitable<'tcx>>(
+    fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(
         &mut self,
         t: &ty::Binder<'tcx, T>,
     ) -> ControlFlow<Self::BreakTy> {
diff --git a/compiler/rustc_infer/src/infer/opaque_types.rs b/compiler/rustc_infer/src/infer/opaque_types.rs
index a657d655f3e..d5c824d4c41 100644
--- a/compiler/rustc_infer/src/infer/opaque_types.rs
+++ b/compiler/rustc_infer/src/infer/opaque_types.rs
@@ -12,8 +12,8 @@ use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::fold::BottomUpFolder;
 use rustc_middle::ty::GenericArgKind;
 use rustc_middle::ty::{
-    self, ir::TypeVisitor, OpaqueHiddenType, OpaqueTypeKey, Ty, TyCtxt, TypeFoldable,
-    TypeSuperVisitable, TypeVisitable,
+    self, OpaqueHiddenType, OpaqueTypeKey, Ty, TyCtxt, TypeFoldable, TypeSuperVisitable,
+    TypeVisitable, TypeVisitableExt, TypeVisitor,
 };
 use rustc_span::Span;
 
@@ -45,7 +45,7 @@ pub struct OpaqueTypeDecl<'tcx> {
 impl<'tcx> InferCtxt<'tcx> {
     /// This is a backwards compatibility hack to prevent breaking changes from
     /// lazy TAIT around RPIT handling.
-    pub fn replace_opaque_types_with_inference_vars<T: TypeFoldable<'tcx>>(
+    pub fn replace_opaque_types_with_inference_vars<T: TypeFoldable<TyCtxt<'tcx>>>(
         &self,
         value: T,
         body_id: LocalDefId,
@@ -427,7 +427,7 @@ impl<'tcx, OP> TypeVisitor<TyCtxt<'tcx>> for ConstrainOpaqueTypeRegionVisitor<'t
 where
     OP: FnMut(ty::Region<'tcx>),
 {
-    fn visit_binder<T: TypeVisitable<'tcx>>(
+    fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(
         &mut self,
         t: &ty::Binder<'tcx, T>,
     ) -> ControlFlow<Self::BreakTy> {
diff --git a/compiler/rustc_infer/src/infer/outlives/components.rs b/compiler/rustc_infer/src/infer/outlives/components.rs
index e3d95669171..ff23087fe8d 100644
--- a/compiler/rustc_infer/src/infer/outlives/components.rs
+++ b/compiler/rustc_infer/src/infer/outlives/components.rs
@@ -4,7 +4,7 @@
 
 use rustc_data_structures::sso::SsoHashSet;
 use rustc_middle::ty::subst::{GenericArg, GenericArgKind};
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
 use smallvec::{smallvec, SmallVec};
 
 #[derive(Debug)]
diff --git a/compiler/rustc_infer/src/infer/outlives/obligations.rs b/compiler/rustc_infer/src/infer/outlives/obligations.rs
index 0194549a886..bbe7d4c63f7 100644
--- a/compiler/rustc_infer/src/infer/outlives/obligations.rs
+++ b/compiler/rustc_infer/src/infer/outlives/obligations.rs
@@ -69,7 +69,7 @@ use crate::traits::{ObligationCause, ObligationCauseCode};
 use rustc_data_structures::undo_log::UndoLogs;
 use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::ty::subst::GenericArgKind;
-use rustc_middle::ty::{self, Region, SubstsRef, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, Region, SubstsRef, Ty, TyCtxt, TypeVisitableExt};
 use smallvec::smallvec;
 
 impl<'tcx> InferCtxt<'tcx> {
diff --git a/compiler/rustc_infer/src/infer/outlives/test_type_match.rs b/compiler/rustc_infer/src/infer/outlives/test_type_match.rs
index 2f7c496161b..3c6cc2b9001 100644
--- a/compiler/rustc_infer/src/infer/outlives/test_type_match.rs
+++ b/compiler/rustc_infer/src/infer/outlives/test_type_match.rs
@@ -1,7 +1,7 @@
 use std::collections::hash_map::Entry;
 
 use rustc_data_structures::fx::FxHashMap;
-use rustc_middle::ty::TypeVisitable;
+use rustc_middle::ty::TypeVisitableExt;
 use rustc_middle::ty::{
     self,
     error::TypeError,
diff --git a/compiler/rustc_infer/src/infer/resolve.rs b/compiler/rustc_infer/src/infer/resolve.rs
index 2c246a5787c..5bb35832930 100644
--- a/compiler/rustc_infer/src/infer/resolve.rs
+++ b/compiler/rustc_infer/src/infer/resolve.rs
@@ -1,11 +1,8 @@
 use super::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use super::{FixupError, FixupResult, InferCtxt, Span};
 use rustc_middle::infer::unify_key::{ConstVariableOrigin, ConstVariableOriginKind};
-use rustc_middle::ty::fold::{
-    ir::{FallibleTypeFolder, TypeFolder},
-    TypeSuperFoldable,
-};
-use rustc_middle::ty::visit::{ir::TypeVisitor, TypeSuperVisitable};
+use rustc_middle::ty::fold::{FallibleTypeFolder, TypeFolder, TypeSuperFoldable};
+use rustc_middle::ty::visit::{TypeSuperVisitable, TypeVisitableExt, TypeVisitor};
 use rustc_middle::ty::{self, Const, InferConst, Ty, TyCtxt, TypeFoldable};
 
 use std::ops::ControlFlow;
@@ -200,7 +197,7 @@ impl<'a, 'tcx> TypeVisitor<TyCtxt<'tcx>> for UnresolvedTypeOrConstFinder<'a, 'tc
 /// then an `Err` result is returned.
 pub fn fully_resolve<'tcx, T>(infcx: &InferCtxt<'tcx>, value: T) -> FixupResult<'tcx, T>
 where
-    T: TypeFoldable<'tcx>,
+    T: TypeFoldable<TyCtxt<'tcx>>,
 {
     value.try_fold_with(&mut FullTypeResolver { infcx })
 }
diff --git a/compiler/rustc_infer/src/infer/sub.rs b/compiler/rustc_infer/src/infer/sub.rs
index bf1b3441547..b4e647dcc9b 100644
--- a/compiler/rustc_infer/src/infer/sub.rs
+++ b/compiler/rustc_infer/src/infer/sub.rs
@@ -3,7 +3,7 @@ use super::{ObligationEmittingRelation, SubregionOrigin};
 
 use crate::traits::{Obligation, PredicateObligations};
 use rustc_middle::ty::relate::{Cause, Relate, RelateResult, TypeRelation};
-use rustc_middle::ty::visit::TypeVisitable;
+use rustc_middle::ty::visit::TypeVisitableExt;
 use rustc_middle::ty::TyVar;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use std::mem;
diff --git a/compiler/rustc_infer/src/traits/structural_impls.rs b/compiler/rustc_infer/src/traits/structural_impls.rs
index 95df6cd62b9..3a5273b0359 100644
--- a/compiler/rustc_infer/src/traits/structural_impls.rs
+++ b/compiler/rustc_infer/src/traits/structural_impls.rs
@@ -2,7 +2,7 @@ use crate::traits;
 use crate::traits::project::Normalized;
 use rustc_middle::ty::fold::{FallibleTypeFolder, TypeFoldable};
 use rustc_middle::ty::visit::{TypeVisitable, TypeVisitor};
-use rustc_middle::ty::{self, ir, TyCtxt};
+use rustc_middle::ty::{self, TyCtxt};
 
 use std::fmt;
 use std::ops::ControlFlow;
@@ -61,8 +61,13 @@ impl<'tcx> fmt::Debug for traits::MismatchedProjectionTypes<'tcx> {
 ///////////////////////////////////////////////////////////////////////////
 // TypeFoldable implementations.
 
-impl<'tcx, O: TypeFoldable<'tcx>> ir::TypeFoldable<TyCtxt<'tcx>> for traits::Obligation<'tcx, O> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx, O: TypeFoldable<TyCtxt<'tcx>>> TypeFoldable<TyCtxt<'tcx>>
+    for traits::Obligation<'tcx, O>
+{
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         Ok(traits::Obligation {
             cause: self.cause,
             recursion_depth: self.recursion_depth,
@@ -72,8 +77,10 @@ impl<'tcx, O: TypeFoldable<'tcx>> ir::TypeFoldable<TyCtxt<'tcx>> for traits::Obl
     }
 }
 
-impl<'tcx, O: TypeVisitable<'tcx>> ir::TypeVisitable<TyCtxt<'tcx>> for traits::Obligation<'tcx, O> {
-    fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+impl<'tcx, O: TypeVisitable<TyCtxt<'tcx>>> TypeVisitable<TyCtxt<'tcx>>
+    for traits::Obligation<'tcx, O>
+{
+    fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
         self.predicate.visit_with(visitor)?;
         self.param_env.visit_with(visitor)
     }
diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index 5e90669d33a..4da7f3f502f 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -1584,7 +1584,7 @@ declare_lint_pass!(
 
 impl<'tcx> LateLintPass<'tcx> for TrivialConstraints {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'tcx>) {
-        use rustc_middle::ty::visit::TypeVisitable;
+        use rustc_middle::ty::visit::TypeVisitableExt;
         use rustc_middle::ty::Clause;
         use rustc_middle::ty::PredicateKind::*;
 
diff --git a/compiler/rustc_lint/src/enum_intrinsics_non_enums.rs b/compiler/rustc_lint/src/enum_intrinsics_non_enums.rs
index 73bd4173270..f1ba192f2bc 100644
--- a/compiler/rustc_lint/src/enum_intrinsics_non_enums.rs
+++ b/compiler/rustc_lint/src/enum_intrinsics_non_enums.rs
@@ -4,7 +4,7 @@ use crate::{
     LateContext, LateLintPass,
 };
 use rustc_hir as hir;
-use rustc_middle::ty::{visit::TypeVisitable, Ty};
+use rustc_middle::ty::{visit::TypeVisitableExt, Ty};
 use rustc_span::{symbol::sym, Span};
 
 declare_lint! {
diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs
index a7f2e9f6eb1..85958c41705 100644
--- a/compiler/rustc_lint/src/types.rs
+++ b/compiler/rustc_lint/src/types.rs
@@ -16,7 +16,9 @@ use rustc_hir as hir;
 use rustc_hir::{is_range_literal, Expr, ExprKind, Node};
 use rustc_middle::ty::layout::{IntegerExt, LayoutOf, SizeSkeleton};
 use rustc_middle::ty::subst::SubstsRef;
-use rustc_middle::ty::{self, AdtKind, DefIdTree, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable};
+use rustc_middle::ty::{
+    self, AdtKind, DefIdTree, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitableExt,
+};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map;
 use rustc_span::symbol::sym;
@@ -1147,7 +1149,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
 
     fn check_for_opaque_ty(&mut self, sp: Span, ty: Ty<'tcx>) -> bool {
         struct ProhibitOpaqueTypes;
-        impl<'tcx> ty::visit::ir::TypeVisitor<TyCtxt<'tcx>> for ProhibitOpaqueTypes {
+        impl<'tcx> ty::visit::TypeVisitor<TyCtxt<'tcx>> for ProhibitOpaqueTypes {
             type BreakTy = Ty<'tcx>;
 
             fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
diff --git a/compiler/rustc_macros/src/type_foldable.rs b/compiler/rustc_macros/src/type_foldable.rs
index 51729a377d9..388e254cd64 100644
--- a/compiler/rustc_macros/src/type_foldable.rs
+++ b/compiler/rustc_macros/src/type_foldable.rs
@@ -37,16 +37,16 @@ pub fn type_foldable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::
                 bind.to_token_stream()
             } else {
                 quote! {
-                    ::rustc_middle::ty::fold::ir::TypeFoldable::try_fold_with(#bind, __folder)?
+                    ::rustc_middle::ty::fold::TypeFoldable::try_fold_with(#bind, __folder)?
                 }
             }
         })
     });
 
     s.bound_impl(
-        quote!(::rustc_middle::ty::fold::ir::TypeFoldable<::rustc_middle::ty::TyCtxt<'tcx>>),
+        quote!(::rustc_middle::ty::fold::TypeFoldable<::rustc_middle::ty::TyCtxt<'tcx>>),
         quote! {
-            fn try_fold_with<__F: ::rustc_middle::ty::fold::FallibleTypeFolder<'tcx>>(
+            fn try_fold_with<__F: ::rustc_middle::ty::fold::FallibleTypeFolder<::rustc_middle::ty::TyCtxt<'tcx>>>(
                 self,
                 __folder: &mut __F
             ) -> Result<Self, __F::Error> {
diff --git a/compiler/rustc_macros/src/type_visitable.rs b/compiler/rustc_macros/src/type_visitable.rs
index 0a16a371fdc..f6f4c4779c3 100644
--- a/compiler/rustc_macros/src/type_visitable.rs
+++ b/compiler/rustc_macros/src/type_visitable.rs
@@ -30,15 +30,15 @@ pub fn type_visitable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2:
     s.add_bounds(synstructure::AddBounds::Generics);
     let body_visit = s.each(|bind| {
         quote! {
-            ::rustc_middle::ty::visit::ir::TypeVisitable::visit_with(#bind, __visitor)?;
+            ::rustc_middle::ty::visit::TypeVisitable::visit_with(#bind, __visitor)?;
         }
     });
     s.bind_with(|_| synstructure::BindStyle::Move);
 
     s.bound_impl(
-        quote!(::rustc_middle::ty::visit::ir::TypeVisitable<::rustc_middle::ty::TyCtxt<'tcx>>),
+        quote!(::rustc_middle::ty::visit::TypeVisitable<::rustc_middle::ty::TyCtxt<'tcx>>),
         quote! {
-            fn visit_with<__V: ::rustc_middle::ty::visit::TypeVisitor<'tcx>>(
+            fn visit_with<__V: ::rustc_middle::ty::visit::TypeVisitor<::rustc_middle::ty::TyCtxt<'tcx>>>(
                 &self,
                 __visitor: &mut __V
             ) -> ::std::ops::ControlFlow<__V::BreakTy> {
diff --git a/compiler/rustc_middle/src/infer/canonical.rs b/compiler/rustc_middle/src/infer/canonical.rs
index bb617e692cc..e134ef8489c 100644
--- a/compiler/rustc_middle/src/infer/canonical.rs
+++ b/compiler/rustc_middle/src/infer/canonical.rs
@@ -42,8 +42,8 @@ pub struct Canonical<'tcx, V> {
 
 pub type CanonicalVarInfos<'tcx> = &'tcx List<CanonicalVarInfo<'tcx>>;
 
-impl<'tcx> ty::ir::TypeFoldable<TyCtxt<'tcx>> for CanonicalVarInfos<'tcx> {
-    fn try_fold_with<F: ty::FallibleTypeFolder<'tcx>>(
+impl<'tcx> ty::TypeFoldable<TyCtxt<'tcx>> for CanonicalVarInfos<'tcx> {
+    fn try_fold_with<F: ty::FallibleTypeFolder<TyCtxt<'tcx>>>(
         self,
         folder: &mut F,
     ) -> Result<Self, F::Error> {
diff --git a/compiler/rustc_middle/src/macros.rs b/compiler/rustc_middle/src/macros.rs
index 57d66ac6a03..a8d71ce030c 100644
--- a/compiler/rustc_middle/src/macros.rs
+++ b/compiler/rustc_middle/src/macros.rs
@@ -69,8 +69,8 @@ macro_rules! CloneLiftImpls {
 macro_rules! TrivialTypeTraversalImpls {
     (for <$tcx:lifetime> { $($ty:ty,)+ }) => {
         $(
-            impl<$tcx> $crate::ty::fold::ir::TypeFoldable<$crate::ty::TyCtxt<$tcx>> for $ty {
-                fn try_fold_with<F: $crate::ty::fold::FallibleTypeFolder<$tcx>>(
+            impl<$tcx> $crate::ty::fold::TypeFoldable<$crate::ty::TyCtxt<$tcx>> for $ty {
+                fn try_fold_with<F: $crate::ty::fold::FallibleTypeFolder<$crate::ty::TyCtxt<$tcx>>>(
                     self,
                     _: &mut F,
                 ) -> ::std::result::Result<Self, F::Error> {
@@ -78,7 +78,7 @@ macro_rules! TrivialTypeTraversalImpls {
                 }
 
                 #[inline]
-                fn fold_with<F: $crate::ty::fold::TypeFolder<$tcx>>(
+                fn fold_with<F: $crate::ty::fold::TypeFolder<$crate::ty::TyCtxt<$tcx>>>(
                     self,
                     _: &mut F,
                 ) -> Self {
@@ -86,9 +86,9 @@ macro_rules! TrivialTypeTraversalImpls {
                 }
             }
 
-            impl<$tcx> $crate::ty::visit::ir::TypeVisitable<$crate::ty::TyCtxt<$tcx>> for $ty {
+            impl<$tcx> $crate::ty::visit::TypeVisitable<$crate::ty::TyCtxt<$tcx>> for $ty {
                 #[inline]
-                fn visit_with<F: $crate::ty::visit::TypeVisitor<$tcx>>(
+                fn visit_with<F: $crate::ty::visit::TypeVisitor<$crate::ty::TyCtxt<$tcx>>>(
                     &self,
                     _: &mut F)
                     -> ::std::ops::ControlFlow<F::BreakTy>
diff --git a/compiler/rustc_middle/src/mir/interpret/queries.rs b/compiler/rustc_middle/src/mir/interpret/queries.rs
index b6c6e9d559c..856d821a5cf 100644
--- a/compiler/rustc_middle/src/mir/interpret/queries.rs
+++ b/compiler/rustc_middle/src/mir/interpret/queries.rs
@@ -2,7 +2,7 @@ use super::{ErrorHandled, EvalToConstValueResult, EvalToValTreeResult, GlobalId}
 
 use crate::mir;
 use crate::ty::subst::InternalSubsts;
-use crate::ty::visit::TypeVisitable;
+use crate::ty::visit::TypeVisitableExt;
 use crate::ty::{self, query::TyCtxtAt, query::TyCtxtEnsure, TyCtxt};
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefId;
diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
index 46184cddd51..ccd8a333866 100644
--- a/compiler/rustc_middle/src/mir/mod.rs
+++ b/compiler/rustc_middle/src/mir/mod.rs
@@ -7,10 +7,10 @@ use crate::mir::interpret::{
 };
 use crate::mir::visit::MirVisitable;
 use crate::ty::codec::{TyDecoder, TyEncoder};
-use crate::ty::fold::{ir::TypeFoldable, FallibleTypeFolder};
+use crate::ty::fold::{FallibleTypeFolder, TypeFoldable};
 use crate::ty::print::{FmtPrinter, Printer};
-use crate::ty::visit::{TypeVisitable, TypeVisitor};
-use crate::ty::{self, ir, DefIdTree, List, Ty, TyCtxt};
+use crate::ty::visit::{TypeVisitable, TypeVisitableExt, TypeVisitor};
+use crate::ty::{self, DefIdTree, List, Ty, TyCtxt};
 use crate::ty::{AdtDef, InstanceDef, ScalarInt, UserTypeAnnotationIndex};
 use crate::ty::{GenericArg, InternalSubsts, SubstsRef};
 
@@ -2755,7 +2755,10 @@ impl UserTypeProjection {
 }
 
 impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for UserTypeProjection {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         Ok(UserTypeProjection {
             base: self.base.try_fold_with(folder)?,
             projs: self.projs.try_fold_with(folder)?,
@@ -2763,8 +2766,11 @@ impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for UserTypeProjection {
     }
 }
 
-impl<'tcx> ir::TypeVisitable<TyCtxt<'tcx>> for UserTypeProjection {
-    fn visit_with<Vs: TypeVisitor<'tcx>>(&self, visitor: &mut Vs) -> ControlFlow<Vs::BreakTy> {
+impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for UserTypeProjection {
+    fn visit_with<Vs: TypeVisitor<TyCtxt<'tcx>>>(
+        &self,
+        visitor: &mut Vs,
+    ) -> ControlFlow<Vs::BreakTy> {
         self.base.visit_with(visitor)
         // Note: there's nothing in `self.proj` to visit.
     }
diff --git a/compiler/rustc_middle/src/mir/type_foldable.rs b/compiler/rustc_middle/src/mir/type_foldable.rs
index ce06a0ef060..d0936d950b3 100644
--- a/compiler/rustc_middle/src/mir/type_foldable.rs
+++ b/compiler/rustc_middle/src/mir/type_foldable.rs
@@ -31,19 +31,28 @@ TrivialTypeTraversalImpls! {
 }
 
 impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for &'tcx [InlineAsmTemplatePiece] {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, _folder: &mut F) -> Result<Self, F::Error> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        _folder: &mut F,
+    ) -> Result<Self, F::Error> {
         Ok(self)
     }
 }
 
 impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for &'tcx [Span] {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, _folder: &mut F) -> Result<Self, F::Error> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        _folder: &mut F,
+    ) -> Result<Self, F::Error> {
         Ok(self)
     }
 }
 
 impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for &'tcx ty::List<PlaceElem<'tcx>> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         ty::util::fold_list(self, folder, |tcx, v| tcx.intern_place_elems(v))
     }
 }
diff --git a/compiler/rustc_middle/src/traits/query.rs b/compiler/rustc_middle/src/traits/query.rs
index 615154a55e5..c4f8718754f 100644
--- a/compiler/rustc_middle/src/traits/query.rs
+++ b/compiler/rustc_middle/src/traits/query.rs
@@ -14,7 +14,7 @@ use rustc_span::source_map::Span;
 
 pub mod type_op {
     use crate::ty::fold::TypeFoldable;
-    use crate::ty::{Predicate, Ty, UserType};
+    use crate::ty::{Predicate, Ty, TyCtxt, UserType};
     use std::fmt;
 
     #[derive(Copy, Clone, Debug, Hash, PartialEq, Eq, HashStable, Lift)]
@@ -64,7 +64,7 @@ pub mod type_op {
 
     impl<'tcx, T> Normalize<T>
     where
-        T: fmt::Debug + TypeFoldable<'tcx>,
+        T: fmt::Debug + TypeFoldable<TyCtxt<'tcx>>,
     {
         pub fn new(value: T) -> Self {
             Self { value }
diff --git a/compiler/rustc_middle/src/traits/solve.rs b/compiler/rustc_middle/src/traits/solve.rs
index bddf84880d2..aadbce9e2ff 100644
--- a/compiler/rustc_middle/src/traits/solve.rs
+++ b/compiler/rustc_middle/src/traits/solve.rs
@@ -3,8 +3,7 @@ use std::ops::ControlFlow;
 use rustc_data_structures::intern::Interned;
 
 use crate::ty::{
-    ir::{self, TypeFoldable, TypeVisitable},
-    FallibleTypeFolder, Ty, TyCtxt, TypeFolder, TypeVisitor,
+    FallibleTypeFolder, Ty, TyCtxt, TypeFoldable, TypeFolder, TypeVisitable, TypeVisitor,
 };
 
 #[derive(Debug, PartialEq, Eq, Copy, Clone, Hash)]
@@ -27,8 +26,11 @@ pub struct ExternalConstraintsData<'tcx> {
 }
 
 impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for ExternalConstraints<'tcx> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
-        Ok(ir::FallibleTypeFolder::interner(folder).intern_external_constraints(
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
+        Ok(FallibleTypeFolder::interner(folder).intern_external_constraints(
             ExternalConstraintsData {
                 regions: (),
                 opaque_types: self
@@ -40,8 +42,8 @@ impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for ExternalConstraints<'tcx> {
         ))
     }
 
-    fn fold_with<F: TypeFolder<'tcx>>(self, folder: &mut F) -> Self {
-        ir::TypeFolder::interner(folder).intern_external_constraints(ExternalConstraintsData {
+    fn fold_with<F: TypeFolder<TyCtxt<'tcx>>>(self, folder: &mut F) -> Self {
+        TypeFolder::interner(folder).intern_external_constraints(ExternalConstraintsData {
             regions: (),
             opaque_types: self.opaque_types.iter().map(|opaque| opaque.fold_with(folder)).collect(),
         })
@@ -49,7 +51,7 @@ impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for ExternalConstraints<'tcx> {
 }
 
 impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for ExternalConstraints<'tcx> {
-    fn visit_with<V: TypeVisitor<'tcx>>(
+    fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(
         &self,
         visitor: &mut V,
     ) -> std::ops::ControlFlow<V::BreakTy> {
diff --git a/compiler/rustc_middle/src/traits/specialization_graph.rs b/compiler/rustc_middle/src/traits/specialization_graph.rs
index 4019cf8ceee..c016f722750 100644
--- a/compiler/rustc_middle/src/traits/specialization_graph.rs
+++ b/compiler/rustc_middle/src/traits/specialization_graph.rs
@@ -1,6 +1,6 @@
 use crate::error::StrictCoherenceNeedsNegativeCoherence;
 use crate::ty::fast_reject::SimplifiedType;
-use crate::ty::visit::TypeVisitable;
+use crate::ty::visit::TypeVisitableExt;
 use crate::ty::{self, TyCtxt};
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_errors::ErrorGuaranteed;
diff --git a/compiler/rustc_middle/src/ty/abstract_const.rs b/compiler/rustc_middle/src/ty/abstract_const.rs
index b7f0a0be75e..f889ce82706 100644
--- a/compiler/rustc_middle/src/ty/abstract_const.rs
+++ b/compiler/rustc_middle/src/ty/abstract_const.rs
@@ -1,6 +1,7 @@
 //! A subset of a mir body used for const evaluatability checking.
 use crate::ty::{
-    self, ir::TypeFolder, Const, EarlyBinder, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable,
+    self, Const, EarlyBinder, Ty, TyCtxt, TypeFoldable, TypeFolder, TypeSuperFoldable,
+    TypeVisitableExt,
 };
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir::def_id::DefId;
@@ -47,7 +48,7 @@ impl<'tcx> TyCtxt<'tcx> {
         Ok(ac?.map(|ac| EarlyBinder(ac)))
     }
 
-    pub fn expand_abstract_consts<T: TypeFoldable<'tcx>>(self, ac: T) -> T {
+    pub fn expand_abstract_consts<T: TypeFoldable<TyCtxt<'tcx>>>(self, ac: T) -> T {
         struct Expander<'tcx> {
             tcx: TyCtxt<'tcx>,
         }
diff --git a/compiler/rustc_middle/src/ty/consts/kind.rs b/compiler/rustc_middle/src/ty/consts/kind.rs
index 52f4414e37b..560caa041a7 100644
--- a/compiler/rustc_middle/src/ty/consts/kind.rs
+++ b/compiler/rustc_middle/src/ty/consts/kind.rs
@@ -4,7 +4,7 @@ use crate::mir::interpret::{AllocId, ConstValue, Scalar};
 use crate::ty::abstract_const::CastKind;
 use crate::ty::subst::{InternalSubsts, SubstsRef};
 use crate::ty::ParamEnv;
-use crate::ty::{self, List, Ty, TyCtxt, TypeVisitable};
+use crate::ty::{self, List, Ty, TyCtxt, TypeVisitableExt};
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir::def_id::DefId;
diff --git a/compiler/rustc_middle/src/ty/diagnostics.rs b/compiler/rustc_middle/src/ty/diagnostics.rs
index bdc58611092..e894e1aaf36 100644
--- a/compiler/rustc_middle/src/ty/diagnostics.rs
+++ b/compiler/rustc_middle/src/ty/diagnostics.rs
@@ -3,10 +3,9 @@
 use std::ops::ControlFlow;
 
 use crate::ty::{
-    ir::{FallibleTypeFolder, TypeVisitor},
-    visit::TypeVisitable,
-    AliasTy, Const, ConstKind, DefIdTree, InferConst, InferTy, Opaque, PolyTraitPredicate,
-    Projection, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable, TypeSuperVisitable,
+    AliasTy, Const, ConstKind, DefIdTree, FallibleTypeFolder, InferConst, InferTy, Opaque,
+    PolyTraitPredicate, Projection, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable,
+    TypeSuperVisitable, TypeVisitable, TypeVisitor,
 };
 
 use rustc_data_structures::fx::FxHashMap;
@@ -95,7 +94,7 @@ pub trait IsSuggestable<'tcx>: Sized {
 
 impl<'tcx, T> IsSuggestable<'tcx> for T
 where
-    T: TypeVisitable<'tcx> + TypeFoldable<'tcx>,
+    T: TypeVisitable<TyCtxt<'tcx>> + TypeFoldable<TyCtxt<'tcx>>,
 {
     fn is_suggestable(self, tcx: TyCtxt<'tcx>, infer_suggestable: bool) -> bool {
         self.visit_with(&mut IsSuggestableVisitor { tcx, infer_suggestable }).is_continue()
diff --git a/compiler/rustc_middle/src/ty/erase_regions.rs b/compiler/rustc_middle/src/ty/erase_regions.rs
index d3b031bf875..38377324832 100644
--- a/compiler/rustc_middle/src/ty/erase_regions.rs
+++ b/compiler/rustc_middle/src/ty/erase_regions.rs
@@ -1,5 +1,5 @@
-use crate::ty::fold::{ir::TypeFolder, TypeFoldable, TypeSuperFoldable};
-use crate::ty::{self, Ty, TyCtxt, TypeFlags};
+use crate::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
+use crate::ty::{self, Ty, TyCtxt, TypeFlags, TypeVisitableExt};
 
 pub(super) fn provide(providers: &mut ty::query::Providers) {
     *providers = ty::query::Providers { erase_regions_ty, ..*providers };
@@ -17,7 +17,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// subtyping, but they are anonymized and normalized as well)..
     pub fn erase_regions<T>(self, value: T) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         // If there's nothing to erase avoid performing the query at all
         if !value.has_type_flags(TypeFlags::HAS_LATE_BOUND | TypeFlags::HAS_FREE_REGIONS) {
@@ -45,7 +45,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for RegionEraserVisitor<'tcx> {
 
     fn fold_binder<T>(&mut self, t: ty::Binder<'tcx, T>) -> ty::Binder<'tcx, T>
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         let u = self.tcx.anonymize_bound_vars(t);
         u.super_fold_with(self)
diff --git a/compiler/rustc_middle/src/ty/fast_reject.rs b/compiler/rustc_middle/src/ty/fast_reject.rs
index 106ce9990e1..59deade0a07 100644
--- a/compiler/rustc_middle/src/ty/fast_reject.rs
+++ b/compiler/rustc_middle/src/ty/fast_reject.rs
@@ -1,6 +1,6 @@
 use crate::mir::Mutability;
 use crate::ty::subst::GenericArgKind;
-use crate::ty::{self, Ty, TyCtxt, TypeVisitable};
+use crate::ty::{self, Ty, TyCtxt, TypeVisitableExt};
 use rustc_hir::def_id::DefId;
 use std::fmt::Debug;
 use std::hash::Hash;
diff --git a/compiler/rustc_middle/src/ty/fold.rs b/compiler/rustc_middle/src/ty/fold.rs
index ee36e60bff1..e8a73832ce4 100644
--- a/compiler/rustc_middle/src/ty/fold.rs
+++ b/compiler/rustc_middle/src/ty/fold.rs
@@ -1,19 +1,10 @@
-use crate::ty::{self, Binder, BoundTy, Ty, TyCtxt, TypeVisitable};
+use crate::ty::{self, Binder, BoundTy, Ty, TyCtxt, TypeVisitableExt};
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_hir::def_id::DefId;
 
 use std::collections::BTreeMap;
 
-pub trait TypeFoldable<'tcx> = ir::TypeFoldable<TyCtxt<'tcx>> + TypeVisitable<'tcx>;
-pub trait TypeSuperFoldable<'tcx> = ir::TypeSuperFoldable<TyCtxt<'tcx>>;
-pub trait TypeFolder<'tcx> = ir::TypeFolder<TyCtxt<'tcx>>;
-pub trait FallibleTypeFolder<'tcx> = ir::FallibleTypeFolder<TyCtxt<'tcx>>;
-
-pub mod ir {
-    pub use rustc_type_ir::fold::{
-        FallibleTypeFolder, TypeFoldable, TypeFolder, TypeSuperFoldable,
-    };
-}
+pub use rustc_type_ir::fold::{FallibleTypeFolder, TypeFoldable, TypeFolder, TypeSuperFoldable};
 
 ///////////////////////////////////////////////////////////////////////////
 // Some sample folders
@@ -30,7 +21,7 @@ where
     pub ct_op: H,
 }
 
-impl<'tcx, F, G, H> ir::TypeFolder<TyCtxt<'tcx>> for BottomUpFolder<'tcx, F, G, H>
+impl<'tcx, F, G, H> TypeFolder<TyCtxt<'tcx>> for BottomUpFolder<'tcx, F, G, H>
 where
     F: FnMut(Ty<'tcx>) -> Ty<'tcx>,
     G: FnMut(ty::Region<'tcx>) -> ty::Region<'tcx>,
@@ -69,7 +60,7 @@ impl<'tcx> TyCtxt<'tcx> {
         mut f: impl FnMut(ty::Region<'tcx>, ty::DebruijnIndex) -> ty::Region<'tcx>,
     ) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         value.fold_with(&mut RegionFolder::new(self, &mut f))
     }
@@ -80,7 +71,7 @@ impl<'tcx> TyCtxt<'tcx> {
         mut f: impl FnMut(ty::Region<'tcx>, ty::DebruijnIndex) -> ty::Region<'tcx>,
     ) -> T
     where
-        T: TypeSuperFoldable<'tcx>,
+        T: TypeSuperFoldable<TyCtxt<'tcx>>,
     {
         value.super_fold_with(&mut RegionFolder::new(self, &mut f))
     }
@@ -120,12 +111,12 @@ impl<'a, 'tcx> RegionFolder<'a, 'tcx> {
     }
 }
 
-impl<'a, 'tcx> ir::TypeFolder<TyCtxt<'tcx>> for RegionFolder<'a, 'tcx> {
+impl<'a, 'tcx> TypeFolder<TyCtxt<'tcx>> for RegionFolder<'a, 'tcx> {
     fn interner(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 
-    fn fold_binder<T: TypeFoldable<'tcx>>(
+    fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
         &mut self,
         t: ty::Binder<'tcx, T>,
     ) -> ty::Binder<'tcx, T> {
@@ -194,7 +185,7 @@ impl<'tcx, D: BoundVarReplacerDelegate<'tcx>> BoundVarReplacer<'tcx, D> {
     }
 }
 
-impl<'tcx, D> ir::TypeFolder<TyCtxt<'tcx>> for BoundVarReplacer<'tcx, D>
+impl<'tcx, D> TypeFolder<TyCtxt<'tcx>> for BoundVarReplacer<'tcx, D>
 where
     D: BoundVarReplacerDelegate<'tcx>,
 {
@@ -202,7 +193,7 @@ where
         self.tcx
     }
 
-    fn fold_binder<T: TypeFoldable<'tcx>>(
+    fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
         &mut self,
         t: ty::Binder<'tcx, T>,
     ) -> ty::Binder<'tcx, T> {
@@ -280,7 +271,7 @@ impl<'tcx> TyCtxt<'tcx> {
     ) -> (T, BTreeMap<ty::BoundRegion, ty::Region<'tcx>>)
     where
         F: FnMut(ty::BoundRegion) -> ty::Region<'tcx>,
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         let mut region_map = BTreeMap::new();
         let real_fld_r = |br: ty::BoundRegion| *region_map.entry(br).or_insert_with(|| fld_r(br));
@@ -295,7 +286,7 @@ impl<'tcx> TyCtxt<'tcx> {
     ) -> T
     where
         F: FnMut(ty::BoundRegion) -> ty::Region<'tcx>,
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         let value = value.skip_binder();
         if !value.has_escaping_bound_vars() {
@@ -314,7 +305,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Replaces all escaping bound vars. The `fld_r` closure replaces escaping
     /// bound regions; the `fld_t` closure replaces escaping bound types and the `fld_c`
     /// closure replaces escaping bound consts.
-    pub fn replace_escaping_bound_vars_uncached<T: TypeFoldable<'tcx>>(
+    pub fn replace_escaping_bound_vars_uncached<T: TypeFoldable<TyCtxt<'tcx>>>(
         self,
         value: T,
         delegate: impl BoundVarReplacerDelegate<'tcx>,
@@ -330,7 +321,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Replaces all types or regions bound by the given `Binder`. The `fld_r`
     /// closure replaces bound regions, the `fld_t` closure replaces bound
     /// types, and `fld_c` replaces bound constants.
-    pub fn replace_bound_vars_uncached<T: TypeFoldable<'tcx>>(
+    pub fn replace_bound_vars_uncached<T: TypeFoldable<TyCtxt<'tcx>>>(
         self,
         value: Binder<'tcx, T>,
         delegate: impl BoundVarReplacerDelegate<'tcx>,
@@ -346,7 +337,7 @@ impl<'tcx> TyCtxt<'tcx> {
         value: ty::Binder<'tcx, T>,
     ) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         self.replace_late_bound_regions_uncached(value, |br| {
             self.mk_re_free(all_outlive_scope, br.kind)
@@ -355,7 +346,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
     pub fn shift_bound_var_indices<T>(self, bound_vars: usize, value: T) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         let shift_bv = |bv: ty::BoundVar| ty::BoundVar::from_usize(bv.as_usize() + bound_vars);
         self.replace_escaping_bound_vars_uncached(
@@ -381,7 +372,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// method lookup and a few other places where precise region relationships are not required.
     pub fn erase_late_bound_regions<T>(self, value: Binder<'tcx, T>) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         self.replace_late_bound_regions(value, |_| self.lifetimes.re_erased).0
     }
@@ -389,7 +380,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Anonymize all bound variables in `value`, this is mostly used to improve caching.
     pub fn anonymize_bound_vars<T>(self, value: Binder<'tcx, T>) -> Binder<'tcx, T>
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         struct Anonymize<'a, 'tcx> {
             tcx: TyCtxt<'tcx>,
@@ -457,12 +448,12 @@ impl<'tcx> Shifter<'tcx> {
     }
 }
 
-impl<'tcx> ir::TypeFolder<TyCtxt<'tcx>> for Shifter<'tcx> {
+impl<'tcx> TypeFolder<TyCtxt<'tcx>> for Shifter<'tcx> {
     fn interner(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 
-    fn fold_binder<T: TypeFoldable<'tcx>>(
+    fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
         &mut self,
         t: ty::Binder<'tcx, T>,
     ) -> ty::Binder<'tcx, T> {
@@ -525,7 +516,7 @@ pub fn shift_region<'tcx>(
 
 pub fn shift_vars<'tcx, T>(tcx: TyCtxt<'tcx>, value: T, amount: u32) -> T
 where
-    T: TypeFoldable<'tcx>,
+    T: TypeFoldable<TyCtxt<'tcx>>,
 {
     debug!("shift_vars(value={:?}, amount={})", value, amount);
 
diff --git a/compiler/rustc_middle/src/ty/instance.rs b/compiler/rustc_middle/src/ty/instance.rs
index c68a344e92c..d07fa0e546f 100644
--- a/compiler/rustc_middle/src/ty/instance.rs
+++ b/compiler/rustc_middle/src/ty/instance.rs
@@ -1,7 +1,7 @@
 use crate::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use crate::ty::print::{FmtPrinter, Printer};
 use crate::ty::{self, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable};
-use crate::ty::{EarlyBinder, InternalSubsts, SubstsRef};
+use crate::ty::{EarlyBinder, InternalSubsts, SubstsRef, TypeVisitableExt};
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir::def::Namespace;
 use rustc_hir::def_id::{CrateNum, DefId};
@@ -589,7 +589,7 @@ impl<'tcx> Instance<'tcx> {
 
     pub fn subst_mir<T>(&self, tcx: TyCtxt<'tcx>, v: &T) -> T
     where
-        T: TypeFoldable<'tcx> + Copy,
+        T: TypeFoldable<TyCtxt<'tcx>> + Copy,
     {
         if let Some(substs) = self.substs_for_mir_body() {
             EarlyBinder(*v).subst(tcx, substs)
@@ -606,7 +606,7 @@ impl<'tcx> Instance<'tcx> {
         v: T,
     ) -> T
     where
-        T: TypeFoldable<'tcx> + Clone,
+        T: TypeFoldable<TyCtxt<'tcx>> + Clone,
     {
         if let Some(substs) = self.substs_for_mir_body() {
             tcx.subst_and_normalize_erasing_regions(substs, param_env, v)
@@ -623,7 +623,7 @@ impl<'tcx> Instance<'tcx> {
         v: T,
     ) -> Result<T, NormalizationError<'tcx>>
     where
-        T: TypeFoldable<'tcx> + Clone,
+        T: TypeFoldable<TyCtxt<'tcx>> + Clone,
     {
         if let Some(substs) = self.substs_for_mir_body() {
             tcx.try_subst_and_normalize_erasing_regions(substs, param_env, v)
@@ -674,7 +674,7 @@ fn polymorphize<'tcx>(
         tcx: TyCtxt<'tcx>,
     }
 
-    impl<'tcx> ty::ir::TypeFolder<TyCtxt<'tcx>> for PolymorphizationFolder<'tcx> {
+    impl<'tcx> ty::TypeFolder<TyCtxt<'tcx>> for PolymorphizationFolder<'tcx> {
         fn interner(&self) -> TyCtxt<'tcx> {
             self.tcx
         }
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index 2d92f377041..146803df02b 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -1,7 +1,7 @@
 use crate::fluent_generated as fluent;
 use crate::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use crate::ty::normalize_erasing_regions::NormalizationError;
-use crate::ty::{self, ReprOptions, Ty, TyCtxt, TypeVisitable};
+use crate::ty::{self, ReprOptions, Ty, TyCtxt, TypeVisitableExt};
 use rustc_errors::{DiagnosticBuilder, Handler, IntoDiagnostic};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
@@ -1121,13 +1121,6 @@ impl From<call::AdjustForForeignAbiError> for FnAbiError<'_> {
 
 impl<'tcx> fmt::Display for FnAbiError<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        #[cfg(bootstrap)]
-        match self {
-            Self::Layout(err) => fmt::Display::fmt(err, f),
-            Self::AdjustForForeignAbi(err) => fmt::Display::fmt(err, f),
-        }
-
-        #[cfg(not(bootstrap))]
         match self {
             Self::Layout(err) => err.fmt(f),
             Self::AdjustForForeignAbi(err) => err.fmt(f),
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index f61fe707ac9..7dcc3ff4e7b 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -12,7 +12,7 @@
 #![allow(rustc::usage_of_ty_tykind)]
 
 pub use self::fold::{FallibleTypeFolder, TypeFoldable, TypeFolder, TypeSuperFoldable};
-pub use self::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitor};
+pub use self::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor};
 pub use self::AssocItemContainer::*;
 pub use self::BorrowKind::*;
 pub use self::IntVarValue::*;
@@ -145,10 +145,6 @@ mod structural_impls;
 mod sty;
 mod typeck_results;
 
-pub mod ir {
-    pub use super::{fold::ir::*, visit::ir::*};
-}
-
 // Data types
 
 pub type RegisteredTools = FxHashSet<Ident>;
@@ -921,14 +917,17 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for Term<'tcx> {
     }
 }
 
-impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for Term<'tcx> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Term<'tcx> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         Ok(self.unpack().try_fold_with(folder)?.pack())
     }
 }
 
-impl<'tcx> ir::TypeVisitable<TyCtxt<'tcx>> for Term<'tcx> {
-    fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Term<'tcx> {
+    fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
         self.unpack().visit_with(visitor)
     }
 }
@@ -1626,8 +1625,8 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for ParamEnv<'tcx> {
     }
 }
 
-impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for ParamEnv<'tcx> {
-    fn try_fold_with<F: ty::fold::FallibleTypeFolder<'tcx>>(
+impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for ParamEnv<'tcx> {
+    fn try_fold_with<F: ty::fold::FallibleTypeFolder<TyCtxt<'tcx>>>(
         self,
         folder: &mut F,
     ) -> Result<Self, F::Error> {
@@ -1639,8 +1638,8 @@ impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for ParamEnv<'tcx> {
     }
 }
 
-impl<'tcx> ir::TypeVisitable<TyCtxt<'tcx>> for ParamEnv<'tcx> {
-    fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for ParamEnv<'tcx> {
+    fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
         self.caller_bounds().visit_with(visitor)?;
         self.reveal().visit_with(visitor)
     }
@@ -1765,7 +1764,7 @@ impl<'tcx> ParamEnv<'tcx> {
     /// `where Box<u32>: Copy`, which are clearly never
     /// satisfiable. We generally want to behave as if they were true,
     /// although the surrounding function is never reachable.
-    pub fn and<T: TypeVisitable<'tcx>>(self, value: T) -> ParamEnvAnd<'tcx, T> {
+    pub fn and<T: TypeVisitable<TyCtxt<'tcx>>>(self, value: T) -> ParamEnvAnd<'tcx, T> {
         match self.reveal() {
             Reveal::UserFacing => ParamEnvAnd { param_env: self, value },
 
diff --git a/compiler/rustc_middle/src/ty/normalize_erasing_regions.rs b/compiler/rustc_middle/src/ty/normalize_erasing_regions.rs
index 825e5fbe232..57c8f3075b0 100644
--- a/compiler/rustc_middle/src/ty/normalize_erasing_regions.rs
+++ b/compiler/rustc_middle/src/ty/normalize_erasing_regions.rs
@@ -9,11 +9,8 @@
 
 use crate::mir;
 use crate::traits::query::NoSolution;
-use crate::ty::fold::{
-    ir::{FallibleTypeFolder, TypeFolder},
-    TypeFoldable,
-};
-use crate::ty::{self, EarlyBinder, SubstsRef, Ty, TyCtxt};
+use crate::ty::fold::{FallibleTypeFolder, TypeFoldable, TypeFolder};
+use crate::ty::{self, EarlyBinder, SubstsRef, Ty, TyCtxt, TypeVisitableExt};
 
 #[derive(Debug, Copy, Clone, HashStable, TyEncodable, TyDecodable)]
 pub enum NormalizationError<'tcx> {
@@ -41,7 +38,7 @@ impl<'tcx> TyCtxt<'tcx> {
     #[tracing::instrument(level = "debug", skip(self, param_env))]
     pub fn normalize_erasing_regions<T>(self, param_env: ty::ParamEnv<'tcx>, value: T) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         debug!(
             "normalize_erasing_regions::<{}>(value={:?}, param_env={:?})",
@@ -73,7 +70,7 @@ impl<'tcx> TyCtxt<'tcx> {
         value: T,
     ) -> Result<T, NormalizationError<'tcx>>
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         debug!(
             "try_normalize_erasing_regions::<{}>(value={:?}, param_env={:?})",
@@ -110,7 +107,7 @@ impl<'tcx> TyCtxt<'tcx> {
         value: ty::Binder<'tcx, T>,
     ) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         let value = self.erase_late_bound_regions(value);
         self.normalize_erasing_regions(param_env, value)
@@ -130,7 +127,7 @@ impl<'tcx> TyCtxt<'tcx> {
         value: ty::Binder<'tcx, T>,
     ) -> Result<T, NormalizationError<'tcx>>
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         let value = self.erase_late_bound_regions(value);
         self.try_normalize_erasing_regions(param_env, value)
@@ -148,7 +145,7 @@ impl<'tcx> TyCtxt<'tcx> {
         value: T,
     ) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         debug!(
             "subst_and_normalize_erasing_regions(\
@@ -172,7 +169,7 @@ impl<'tcx> TyCtxt<'tcx> {
         value: T,
     ) -> Result<T, NormalizationError<'tcx>>
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         debug!(
             "subst_and_normalize_erasing_regions(\
diff --git a/compiler/rustc_middle/src/ty/opaque_types.rs b/compiler/rustc_middle/src/ty/opaque_types.rs
index 8aeef4684b3..195bd8a3818 100644
--- a/compiler/rustc_middle/src/ty/opaque_types.rs
+++ b/compiler/rustc_middle/src/ty/opaque_types.rs
@@ -1,9 +1,7 @@
 use crate::error::ConstNotUsedTraitAlias;
-use crate::ty::fold::{ir::TypeFolder, TypeSuperFoldable};
+use crate::ty::fold::{TypeFolder, TypeSuperFoldable};
 use crate::ty::subst::{GenericArg, GenericArgKind};
-#[cfg(not(bootstrap))]
-use crate::ty::TypeFoldable;
-use crate::ty::{self, Ty, TyCtxt};
+use crate::ty::{self, Ty, TyCtxt, TypeFoldable};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_span::def_id::DefId;
 use rustc_span::Span;
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
index a101127104d..6a053c368d8 100644
--- a/compiler/rustc_middle/src/ty/print/pretty.rs
+++ b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -1,7 +1,7 @@
 use crate::mir::interpret::{AllocRange, GlobalAlloc, Pointer, Provenance, Scalar};
 use crate::ty::{
     self, ConstInt, DefIdTree, ParamConst, ScalarInt, Term, TermKind, Ty, TyCtxt, TypeFoldable,
-    TypeSuperFoldable, TypeSuperVisitable, TypeVisitable,
+    TypeSuperFoldable, TypeSuperVisitable, TypeVisitable, TypeVisitableExt,
 };
 use crate::ty::{GenericArg, GenericArgKind};
 use rustc_apfloat::ieee::{Double, Single};
@@ -225,7 +225,7 @@ pub trait PrettyPrinter<'tcx>:
 
     fn in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, Self::Error>
     where
-        T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
+        T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<TyCtxt<'tcx>>,
     {
         value.as_ref().skip_binder().print(self)
     }
@@ -236,7 +236,7 @@ pub trait PrettyPrinter<'tcx>:
         f: F,
     ) -> Result<Self, Self::Error>
     where
-        T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
+        T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<TyCtxt<'tcx>>,
     {
         f(value.as_ref().skip_binder(), self)
     }
@@ -2033,7 +2033,7 @@ impl<'tcx> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx> {
 
     fn in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, Self::Error>
     where
-        T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
+        T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<TyCtxt<'tcx>>,
     {
         self.pretty_in_binder(value)
     }
@@ -2044,7 +2044,7 @@ impl<'tcx> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx> {
         f: C,
     ) -> Result<Self, Self::Error>
     where
-        T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<'tcx>,
+        T: Print<'tcx, Self, Output = Self, Error = Self::Error> + TypeFoldable<TyCtxt<'tcx>>,
     {
         self.pretty_wrap_binder(value, f)
     }
@@ -2224,12 +2224,12 @@ struct RegionFolder<'a, 'tcx> {
             ),
 }
 
-impl<'a, 'tcx> ty::ir::TypeFolder<TyCtxt<'tcx>> for RegionFolder<'a, 'tcx> {
+impl<'a, 'tcx> ty::TypeFolder<TyCtxt<'tcx>> for RegionFolder<'a, 'tcx> {
     fn interner(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 
-    fn fold_binder<T: TypeFoldable<'tcx>>(
+    fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
         &mut self,
         t: ty::Binder<'tcx, T>,
     ) -> ty::Binder<'tcx, T> {
@@ -2289,7 +2289,7 @@ impl<'tcx> FmtPrinter<'_, 'tcx> {
         value: &ty::Binder<'tcx, T>,
     ) -> Result<(Self, T, BTreeMap<ty::BoundRegion, ty::Region<'tcx>>), fmt::Error>
     where
-        T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
+        T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<TyCtxt<'tcx>>,
     {
         fn name_by_region_index(
             index: usize,
@@ -2452,7 +2452,7 @@ impl<'tcx> FmtPrinter<'_, 'tcx> {
 
     pub fn pretty_in_binder<T>(self, value: &ty::Binder<'tcx, T>) -> Result<Self, fmt::Error>
     where
-        T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
+        T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<TyCtxt<'tcx>>,
     {
         let old_region_index = self.region_index;
         let (new, new_value, _) = self.name_all_regions(value)?;
@@ -2468,7 +2468,7 @@ impl<'tcx> FmtPrinter<'_, 'tcx> {
         f: C,
     ) -> Result<Self, fmt::Error>
     where
-        T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<'tcx>,
+        T: Print<'tcx, Self, Output = Self, Error = fmt::Error> + TypeFoldable<TyCtxt<'tcx>>,
     {
         let old_region_index = self.region_index;
         let (new, new_value, _) = self.name_all_regions(value)?;
@@ -2480,7 +2480,7 @@ impl<'tcx> FmtPrinter<'_, 'tcx> {
 
     fn prepare_region_info<T>(&mut self, value: &ty::Binder<'tcx, T>)
     where
-        T: TypeVisitable<'tcx>,
+        T: TypeVisitable<TyCtxt<'tcx>>,
     {
         struct RegionNameCollector<'tcx> {
             used_region_names: FxHashSet<Symbol>,
@@ -2496,7 +2496,7 @@ impl<'tcx> FmtPrinter<'_, 'tcx> {
             }
         }
 
-        impl<'tcx> ty::visit::ir::TypeVisitor<TyCtxt<'tcx>> for RegionNameCollector<'tcx> {
+        impl<'tcx> ty::visit::TypeVisitor<TyCtxt<'tcx>> for RegionNameCollector<'tcx> {
             type BreakTy = ();
 
             fn visit_region(&mut self, r: ty::Region<'tcx>) -> ControlFlow<Self::BreakTy> {
@@ -2533,7 +2533,7 @@ impl<'tcx> FmtPrinter<'_, 'tcx> {
 
 impl<'tcx, T, P: PrettyPrinter<'tcx>> Print<'tcx, P> for ty::Binder<'tcx, T>
 where
-    T: Print<'tcx, P, Output = P, Error = P::Error> + TypeFoldable<'tcx>,
+    T: Print<'tcx, P, Output = P, Error = P::Error> + TypeFoldable<TyCtxt<'tcx>>,
 {
     type Output = P;
     type Error = P::Error;
diff --git a/compiler/rustc_middle/src/ty/relate.rs b/compiler/rustc_middle/src/ty/relate.rs
index 2ba25e8bfad..3dfa5e953b5 100644
--- a/compiler/rustc_middle/src/ty/relate.rs
+++ b/compiler/rustc_middle/src/ty/relate.rs
@@ -105,7 +105,7 @@ pub trait TypeRelation<'tcx>: Sized {
         T: Relate<'tcx>;
 }
 
-pub trait Relate<'tcx>: TypeFoldable<'tcx> + PartialEq + Copy {
+pub trait Relate<'tcx>: TypeFoldable<TyCtxt<'tcx>> + PartialEq + Copy {
     fn relate<R: TypeRelation<'tcx>>(
         relation: &mut R,
         a: Self,
diff --git a/compiler/rustc_middle/src/ty/structural_impls.rs b/compiler/rustc_middle/src/ty/structural_impls.rs
index 573105fd8c0..fbe5d8ccff5 100644
--- a/compiler/rustc_middle/src/ty/structural_impls.rs
+++ b/compiler/rustc_middle/src/ty/structural_impls.rs
@@ -5,10 +5,10 @@
 
 use crate::mir::interpret;
 use crate::mir::{Field, ProjectionKind};
-use crate::ty::fold::{ir::TypeSuperFoldable, FallibleTypeFolder, TypeFoldable};
+use crate::ty::fold::{FallibleTypeFolder, TypeFoldable, TypeSuperFoldable};
 use crate::ty::print::{with_no_trimmed_paths, FmtPrinter, Printer};
-use crate::ty::visit::{ir::TypeSuperVisitable, TypeVisitable, TypeVisitor};
-use crate::ty::{self, ir, AliasTy, InferConst, Lift, Term, TermKind, Ty, TyCtxt};
+use crate::ty::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitor};
+use crate::ty::{self, AliasTy, InferConst, Lift, Term, TermKind, Ty, TyCtxt};
 use rustc_hir::def::Namespace;
 use rustc_index::vec::{Idx, IndexVec};
 use rustc_target::abi::TyAndLayout;
@@ -372,32 +372,41 @@ impl<'a, 'tcx> Lift<'tcx> for ty::ParamEnv<'a> {
 // Traversal implementations.
 
 /// AdtDefs are basically the same as a DefId.
-impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for ty::AdtDef<'tcx> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, _folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for ty::AdtDef<'tcx> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        _folder: &mut F,
+    ) -> Result<Self, F::Error> {
         Ok(self)
     }
 }
 
-impl<'tcx> ir::TypeVisitable<TyCtxt<'tcx>> for ty::AdtDef<'tcx> {
-    fn visit_with<V: TypeVisitor<'tcx>>(&self, _visitor: &mut V) -> ControlFlow<V::BreakTy> {
+impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for ty::AdtDef<'tcx> {
+    fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(
+        &self,
+        _visitor: &mut V,
+    ) -> ControlFlow<V::BreakTy> {
         ControlFlow::Continue(())
     }
 }
 
-impl<'tcx, T: TypeFoldable<'tcx>> ir::TypeFoldable<TyCtxt<'tcx>> for ty::Binder<'tcx, T> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx, T: TypeFoldable<TyCtxt<'tcx>>> TypeFoldable<TyCtxt<'tcx>> for ty::Binder<'tcx, T> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         folder.try_fold_binder(self)
     }
 }
 
-impl<'tcx, T: TypeVisitable<'tcx>> ir::TypeVisitable<TyCtxt<'tcx>> for ty::Binder<'tcx, T> {
-    fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+impl<'tcx, T: TypeVisitable<TyCtxt<'tcx>>> TypeVisitable<TyCtxt<'tcx>> for ty::Binder<'tcx, T> {
+    fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
         visitor.visit_binder(self)
     }
 }
 
-impl<'tcx, T: TypeFoldable<'tcx>> TypeSuperFoldable<TyCtxt<'tcx>> for ty::Binder<'tcx, T> {
-    fn try_super_fold_with<F: FallibleTypeFolder<'tcx>>(
+impl<'tcx, T: TypeFoldable<TyCtxt<'tcx>>> TypeSuperFoldable<TyCtxt<'tcx>> for ty::Binder<'tcx, T> {
+    fn try_super_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
         self,
         folder: &mut F,
     ) -> Result<Self, F::Error> {
@@ -405,44 +414,61 @@ impl<'tcx, T: TypeFoldable<'tcx>> TypeSuperFoldable<TyCtxt<'tcx>> for ty::Binder
     }
 }
 
-impl<'tcx, T: TypeVisitable<'tcx>> TypeSuperVisitable<TyCtxt<'tcx>> for ty::Binder<'tcx, T> {
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+impl<'tcx, T: TypeVisitable<TyCtxt<'tcx>>> TypeSuperVisitable<TyCtxt<'tcx>>
+    for ty::Binder<'tcx, T>
+{
+    fn super_visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(
+        &self,
+        visitor: &mut V,
+    ) -> ControlFlow<V::BreakTy> {
         self.as_ref().skip_binder().visit_with(visitor)
     }
 }
 
-impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         ty::util::fold_list(self, folder, |tcx, v| tcx.intern_poly_existential_predicates(v))
     }
 }
 
-impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for &'tcx ty::List<ty::Const<'tcx>> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for &'tcx ty::List<ty::Const<'tcx>> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         ty::util::fold_list(self, folder, |tcx, v| tcx.intern_const_list(v))
     }
 }
 
-impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for &'tcx ty::List<ProjectionKind> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for &'tcx ty::List<ProjectionKind> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         ty::util::fold_list(self, folder, |tcx, v| tcx.intern_projs(v))
     }
 }
 
-impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for Ty<'tcx> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Ty<'tcx> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         folder.try_fold_ty(self)
     }
 }
 
-impl<'tcx> ir::TypeVisitable<TyCtxt<'tcx>> for Ty<'tcx> {
-    fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Ty<'tcx> {
+    fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
         visitor.visit_ty(*self)
     }
 }
 
 impl<'tcx> TypeSuperFoldable<TyCtxt<'tcx>> for Ty<'tcx> {
-    fn try_super_fold_with<F: FallibleTypeFolder<'tcx>>(
+    fn try_super_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
         self,
         folder: &mut F,
     ) -> Result<Self, F::Error> {
@@ -492,7 +518,10 @@ impl<'tcx> TypeSuperFoldable<TyCtxt<'tcx>> for Ty<'tcx> {
 }
 
 impl<'tcx> TypeSuperVisitable<TyCtxt<'tcx>> for Ty<'tcx> {
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+    fn super_visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(
+        &self,
+        visitor: &mut V,
+    ) -> ControlFlow<V::BreakTy> {
         match self.kind() {
             ty::RawPtr(ref tm) => tm.visit_with(visitor),
             ty::Array(typ, sz) => {
@@ -535,20 +564,23 @@ impl<'tcx> TypeSuperVisitable<TyCtxt<'tcx>> for Ty<'tcx> {
     }
 }
 
-impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for ty::Region<'tcx> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for ty::Region<'tcx> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         folder.try_fold_region(self)
     }
 }
 
-impl<'tcx> ir::TypeVisitable<TyCtxt<'tcx>> for ty::Region<'tcx> {
-    fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for ty::Region<'tcx> {
+    fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
         visitor.visit_region(*self)
     }
 }
 
 impl<'tcx> TypeSuperFoldable<TyCtxt<'tcx>> for ty::Region<'tcx> {
-    fn try_super_fold_with<F: FallibleTypeFolder<'tcx>>(
+    fn try_super_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
         self,
         _folder: &mut F,
     ) -> Result<Self, F::Error> {
@@ -557,25 +589,31 @@ impl<'tcx> TypeSuperFoldable<TyCtxt<'tcx>> for ty::Region<'tcx> {
 }
 
 impl<'tcx> TypeSuperVisitable<TyCtxt<'tcx>> for ty::Region<'tcx> {
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, _visitor: &mut V) -> ControlFlow<V::BreakTy> {
+    fn super_visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(
+        &self,
+        _visitor: &mut V,
+    ) -> ControlFlow<V::BreakTy> {
         ControlFlow::Continue(())
     }
 }
 
-impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for ty::Predicate<'tcx> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for ty::Predicate<'tcx> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         folder.try_fold_predicate(self)
     }
 }
 
-impl<'tcx> ir::TypeVisitable<TyCtxt<'tcx>> for ty::Predicate<'tcx> {
-    fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for ty::Predicate<'tcx> {
+    fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
         visitor.visit_predicate(*self)
     }
 }
 
 impl<'tcx> TypeSuperFoldable<TyCtxt<'tcx>> for ty::Predicate<'tcx> {
-    fn try_super_fold_with<F: FallibleTypeFolder<'tcx>>(
+    fn try_super_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
         self,
         folder: &mut F,
     ) -> Result<Self, F::Error> {
@@ -585,31 +623,40 @@ impl<'tcx> TypeSuperFoldable<TyCtxt<'tcx>> for ty::Predicate<'tcx> {
 }
 
 impl<'tcx> TypeSuperVisitable<TyCtxt<'tcx>> for ty::Predicate<'tcx> {
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+    fn super_visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(
+        &self,
+        visitor: &mut V,
+    ) -> ControlFlow<V::BreakTy> {
         self.kind().visit_with(visitor)
     }
 }
 
-impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for &'tcx ty::List<ty::Predicate<'tcx>> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for &'tcx ty::List<ty::Predicate<'tcx>> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         ty::util::fold_list(self, folder, |tcx, v| tcx.intern_predicates(v))
     }
 }
 
-impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for ty::Const<'tcx> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for ty::Const<'tcx> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         folder.try_fold_const(self)
     }
 }
 
-impl<'tcx> ir::TypeVisitable<TyCtxt<'tcx>> for ty::Const<'tcx> {
-    fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for ty::Const<'tcx> {
+    fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
         visitor.visit_const(*self)
     }
 }
 
 impl<'tcx> TypeSuperFoldable<TyCtxt<'tcx>> for ty::Const<'tcx> {
-    fn try_super_fold_with<F: FallibleTypeFolder<'tcx>>(
+    fn try_super_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
         self,
         folder: &mut F,
     ) -> Result<Self, F::Error> {
@@ -624,32 +671,44 @@ impl<'tcx> TypeSuperFoldable<TyCtxt<'tcx>> for ty::Const<'tcx> {
 }
 
 impl<'tcx> TypeSuperVisitable<TyCtxt<'tcx>> for ty::Const<'tcx> {
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+    fn super_visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(
+        &self,
+        visitor: &mut V,
+    ) -> ControlFlow<V::BreakTy> {
         self.ty().visit_with(visitor)?;
         self.kind().visit_with(visitor)
     }
 }
 
-impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for InferConst<'tcx> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, _folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for InferConst<'tcx> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        _folder: &mut F,
+    ) -> Result<Self, F::Error> {
         Ok(self)
     }
 }
 
-impl<'tcx> ir::TypeVisitable<TyCtxt<'tcx>> for InferConst<'tcx> {
-    fn visit_with<V: TypeVisitor<'tcx>>(&self, _visitor: &mut V) -> ControlFlow<V::BreakTy> {
+impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for InferConst<'tcx> {
+    fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(
+        &self,
+        _visitor: &mut V,
+    ) -> ControlFlow<V::BreakTy> {
         ControlFlow::Continue(())
     }
 }
 
 impl<'tcx> TypeSuperVisitable<TyCtxt<'tcx>> for ty::UnevaluatedConst<'tcx> {
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+    fn super_visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(
+        &self,
+        visitor: &mut V,
+    ) -> ControlFlow<V::BreakTy> {
         self.substs.visit_with(visitor)
     }
 }
 
-impl<'tcx> ir::TypeVisitable<TyCtxt<'tcx>> for TyAndLayout<'tcx, Ty<'tcx>> {
-    fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for TyAndLayout<'tcx, Ty<'tcx>> {
+    fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
         visitor.visit_ty(self.ty)
     }
 }
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index 35ff71d8885..7563656f91b 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -7,10 +7,8 @@ use crate::ty::subst::{GenericArg, InternalSubsts, SubstsRef};
 use crate::ty::visit::ValidateBoundVars;
 use crate::ty::InferTy::*;
 use crate::ty::{
-    self,
-    ir::{FallibleTypeFolder, TypeVisitor},
-    AdtDef, DefIdTree, Discr, Term, Ty, TyCtxt, TypeFlags, TypeFoldable, TypeSuperFoldable,
-    TypeSuperVisitable, TypeVisitable,
+    self, AdtDef, DefIdTree, Discr, FallibleTypeFolder, Term, Ty, TyCtxt, TypeFlags, TypeFoldable,
+    TypeSuperFoldable, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor,
 };
 use crate::ty::{List, ParamEnv};
 use hir::def::DefKind;
@@ -985,7 +983,7 @@ pub struct Binder<'tcx, T>(T, &'tcx List<BoundVariableKind>);
 
 impl<'tcx, T> Binder<'tcx, T>
 where
-    T: TypeVisitable<'tcx>,
+    T: TypeVisitable<TyCtxt<'tcx>>,
 {
     /// Wraps `value` in a binder, asserting that `value` does not
     /// contain any bound vars that would be bound by the
@@ -1053,14 +1051,14 @@ impl<'tcx, T> Binder<'tcx, T> {
         Binder(value, self.1)
     }
 
-    pub fn map_bound_ref<F, U: TypeVisitable<'tcx>>(&self, f: F) -> Binder<'tcx, U>
+    pub fn map_bound_ref<F, U: TypeVisitable<TyCtxt<'tcx>>>(&self, f: F) -> Binder<'tcx, U>
     where
         F: FnOnce(&T) -> U,
     {
         self.as_ref().map_bound(f)
     }
 
-    pub fn map_bound<F, U: TypeVisitable<'tcx>>(self, f: F) -> Binder<'tcx, U>
+    pub fn map_bound<F, U: TypeVisitable<TyCtxt<'tcx>>>(self, f: F) -> Binder<'tcx, U>
     where
         F: FnOnce(T) -> U,
     {
@@ -1072,7 +1070,10 @@ impl<'tcx, T> Binder<'tcx, T> {
         Binder(value, self.1)
     }
 
-    pub fn try_map_bound<F, U: TypeVisitable<'tcx>, E>(self, f: F) -> Result<Binder<'tcx, U>, E>
+    pub fn try_map_bound<F, U: TypeVisitable<TyCtxt<'tcx>>, E>(
+        self,
+        f: F,
+    ) -> Result<Binder<'tcx, U>, E>
     where
         F: FnOnce(T) -> Result<U, E>,
     {
@@ -1095,7 +1096,7 @@ impl<'tcx, T> Binder<'tcx, T> {
     /// in `bind`. This may be (debug) asserted in the future.
     pub fn rebind<U>(&self, value: U) -> Binder<'tcx, U>
     where
-        U: TypeVisitable<'tcx>,
+        U: TypeVisitable<TyCtxt<'tcx>>,
     {
         if cfg!(debug_assertions) {
             let mut validator = ValidateBoundVars::new(self.bound_vars());
@@ -1116,7 +1117,7 @@ impl<'tcx, T> Binder<'tcx, T> {
     /// would not be that useful.)
     pub fn no_bound_vars(self) -> Option<T>
     where
-        T: TypeVisitable<'tcx>,
+        T: TypeVisitable<TyCtxt<'tcx>>,
     {
         if self.0.has_escaping_bound_vars() { None } else { Some(self.skip_binder()) }
     }
@@ -1164,7 +1165,7 @@ impl<'tcx> FallibleTypeFolder<TyCtxt<'tcx>> for SkipBindersAt<'tcx> {
 
     fn try_fold_binder<T>(&mut self, t: Binder<'tcx, T>) -> Result<Binder<'tcx, T>, Self::Error>
     where
-        T: ty::TypeFoldable<'tcx>,
+        T: ty::TypeFoldable<TyCtxt<'tcx>>,
     {
         self.index.shift_in(1);
         let value = t.try_map_bound(|t| t.try_fold_with(self));
diff --git a/compiler/rustc_middle/src/ty/subst.rs b/compiler/rustc_middle/src/ty/subst.rs
index 6b4a6a17aef..1ed3ef5745b 100644
--- a/compiler/rustc_middle/src/ty/subst.rs
+++ b/compiler/rustc_middle/src/ty/subst.rs
@@ -1,10 +1,10 @@
 // Type substitutions.
 
 use crate::ty::codec::{TyDecoder, TyEncoder};
-use crate::ty::fold::{ir::TypeFolder, FallibleTypeFolder, TypeFoldable, TypeSuperFoldable};
+use crate::ty::fold::{FallibleTypeFolder, TypeFoldable, TypeFolder, TypeSuperFoldable};
 use crate::ty::sty::{ClosureSubsts, GeneratorSubsts, InlineConstSubsts};
-use crate::ty::visit::{TypeVisitable, TypeVisitor};
-use crate::ty::{self, ir, Lift, List, ParamConst, Ty, TyCtxt};
+use crate::ty::visit::{TypeVisitable, TypeVisitableExt, TypeVisitor};
+use crate::ty::{self, Lift, List, ParamConst, Ty, TyCtxt};
 
 use rustc_data_structures::intern::Interned;
 use rustc_errors::{DiagnosticArgValue, IntoDiagnosticArg};
@@ -227,8 +227,11 @@ impl<'a, 'tcx> Lift<'tcx> for GenericArg<'a> {
     }
 }
 
-impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for GenericArg<'tcx> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for GenericArg<'tcx> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         match self.unpack() {
             GenericArgKind::Lifetime(lt) => lt.try_fold_with(folder).map(Into::into),
             GenericArgKind::Type(ty) => ty.try_fold_with(folder).map(Into::into),
@@ -237,8 +240,8 @@ impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for GenericArg<'tcx> {
     }
 }
 
-impl<'tcx> ir::TypeVisitable<TyCtxt<'tcx>> for GenericArg<'tcx> {
-    fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for GenericArg<'tcx> {
+    fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
         match self.unpack() {
             GenericArgKind::Lifetime(lt) => lt.visit_with(visitor),
             GenericArgKind::Type(ty) => ty.visit_with(visitor),
@@ -473,8 +476,11 @@ impl<'tcx> InternalSubsts<'tcx> {
     }
 }
 
-impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for SubstsRef<'tcx> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for SubstsRef<'tcx> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         // This code is hot enough that it's worth specializing for the most
         // common length lists, to avoid the overhead of `SmallVec` creation.
         // The match arms are in order of frequency. The 1, 2, and 0 cases are
@@ -505,8 +511,11 @@ impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for SubstsRef<'tcx> {
     }
 }
 
-impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for &'tcx ty::List<Ty<'tcx>> {
-    fn try_fold_with<F: FallibleTypeFolder<'tcx>>(self, folder: &mut F) -> Result<Self, F::Error> {
+impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for &'tcx ty::List<Ty<'tcx>> {
+    fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
+        self,
+        folder: &mut F,
+    ) -> Result<Self, F::Error> {
         // This code is fairly hot, though not as hot as `SubstsRef`.
         //
         // When compiling stage 2, I get the following results:
@@ -537,9 +546,9 @@ impl<'tcx> ir::TypeFoldable<TyCtxt<'tcx>> for &'tcx ty::List<Ty<'tcx>> {
     }
 }
 
-impl<'tcx, T: TypeVisitable<'tcx>> ir::TypeVisitable<TyCtxt<'tcx>> for &'tcx ty::List<T> {
+impl<'tcx, T: TypeVisitable<TyCtxt<'tcx>>> TypeVisitable<TyCtxt<'tcx>> for &'tcx ty::List<T> {
     #[inline]
-    fn visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
+    fn visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy> {
         self.iter().try_for_each(|t| t.visit_with(visitor))
     }
 }
@@ -555,8 +564,8 @@ impl<'tcx, T: TypeVisitable<'tcx>> ir::TypeVisitable<TyCtxt<'tcx>> for &'tcx ty:
 pub struct EarlyBinder<T>(pub T);
 
 /// For early binders, you should first call `subst` before using any visitors.
-impl<'tcx, T> !ir::TypeFoldable<TyCtxt<'tcx>> for ty::EarlyBinder<T> {}
-impl<'tcx, T> !ir::TypeVisitable<TyCtxt<'tcx>> for ty::EarlyBinder<T> {}
+impl<'tcx, T> !TypeFoldable<TyCtxt<'tcx>> for ty::EarlyBinder<T> {}
+impl<'tcx, T> !TypeVisitable<TyCtxt<'tcx>> for ty::EarlyBinder<T> {}
 
 impl<T> EarlyBinder<T> {
     pub fn as_ref(&self) -> EarlyBinder<&T> {
@@ -617,7 +626,7 @@ impl<T, U> EarlyBinder<(T, U)> {
 
 impl<'tcx, 's, I: IntoIterator> EarlyBinder<I>
 where
-    I::Item: TypeFoldable<'tcx>,
+    I::Item: TypeFoldable<TyCtxt<'tcx>>,
 {
     pub fn subst_iter(
         self,
@@ -636,7 +645,7 @@ pub struct SubstIter<'s, 'tcx, I: IntoIterator> {
 
 impl<'tcx, I: IntoIterator> Iterator for SubstIter<'_, 'tcx, I>
 where
-    I::Item: TypeFoldable<'tcx>,
+    I::Item: TypeFoldable<TyCtxt<'tcx>>,
 {
     type Item = I::Item;
 
@@ -652,7 +661,7 @@ where
 impl<'tcx, I: IntoIterator> DoubleEndedIterator for SubstIter<'_, 'tcx, I>
 where
     I::IntoIter: DoubleEndedIterator,
-    I::Item: TypeFoldable<'tcx>,
+    I::Item: TypeFoldable<TyCtxt<'tcx>>,
 {
     fn next_back(&mut self) -> Option<Self::Item> {
         Some(EarlyBinder(self.it.next_back()?).subst(self.tcx, self.substs))
@@ -662,14 +671,14 @@ where
 impl<'tcx, I: IntoIterator> ExactSizeIterator for SubstIter<'_, 'tcx, I>
 where
     I::IntoIter: ExactSizeIterator,
-    I::Item: TypeFoldable<'tcx>,
+    I::Item: TypeFoldable<TyCtxt<'tcx>>,
 {
 }
 
 impl<'tcx, 's, I: IntoIterator> EarlyBinder<I>
 where
     I::Item: Deref,
-    <I::Item as Deref>::Target: Copy + TypeFoldable<'tcx>,
+    <I::Item as Deref>::Target: Copy + TypeFoldable<TyCtxt<'tcx>>,
 {
     pub fn subst_iter_copied(
         self,
@@ -689,7 +698,7 @@ pub struct SubstIterCopied<'a, 'tcx, I: IntoIterator> {
 impl<'tcx, I: IntoIterator> Iterator for SubstIterCopied<'_, 'tcx, I>
 where
     I::Item: Deref,
-    <I::Item as Deref>::Target: Copy + TypeFoldable<'tcx>,
+    <I::Item as Deref>::Target: Copy + TypeFoldable<TyCtxt<'tcx>>,
 {
     type Item = <I::Item as Deref>::Target;
 
@@ -706,7 +715,7 @@ impl<'tcx, I: IntoIterator> DoubleEndedIterator for SubstIterCopied<'_, 'tcx, I>
 where
     I::IntoIter: DoubleEndedIterator,
     I::Item: Deref,
-    <I::Item as Deref>::Target: Copy + TypeFoldable<'tcx>,
+    <I::Item as Deref>::Target: Copy + TypeFoldable<TyCtxt<'tcx>>,
 {
     fn next_back(&mut self) -> Option<Self::Item> {
         Some(EarlyBinder(*self.it.next_back()?).subst(self.tcx, self.substs))
@@ -717,7 +726,7 @@ impl<'tcx, I: IntoIterator> ExactSizeIterator for SubstIterCopied<'_, 'tcx, I>
 where
     I::IntoIter: ExactSizeIterator,
     I::Item: Deref,
-    <I::Item as Deref>::Target: Copy + TypeFoldable<'tcx>,
+    <I::Item as Deref>::Target: Copy + TypeFoldable<TyCtxt<'tcx>>,
 {
 }
 
@@ -743,7 +752,7 @@ impl<T: Iterator> Iterator for EarlyBinderIter<T> {
     }
 }
 
-impl<'tcx, T: TypeFoldable<'tcx>> ty::EarlyBinder<T> {
+impl<'tcx, T: TypeFoldable<TyCtxt<'tcx>>> ty::EarlyBinder<T> {
     pub fn subst(self, tcx: TyCtxt<'tcx>, substs: &[GenericArg<'tcx>]) -> T {
         let mut folder = SubstFolder { tcx, substs, binders_passed: 0 };
         self.0.fold_with(&mut folder)
@@ -784,7 +793,7 @@ impl<'a, 'tcx> TypeFolder<TyCtxt<'tcx>> for SubstFolder<'a, 'tcx> {
         self.tcx
     }
 
-    fn fold_binder<T: TypeFoldable<'tcx>>(
+    fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
         &mut self,
         t: ty::Binder<'tcx, T>,
     ) -> ty::Binder<'tcx, T> {
@@ -977,7 +986,7 @@ impl<'a, 'tcx> SubstFolder<'a, 'tcx> {
     /// As indicated in the diagram, here the same type `&'a i32` is substituted once, but in the
     /// first case we do not increase the De Bruijn index and in the second case we do. The reason
     /// is that only in the second case have we passed through a fn binder.
-    fn shift_vars_through_binders<T: TypeFoldable<'tcx>>(&self, val: T) -> T {
+    fn shift_vars_through_binders<T: TypeFoldable<TyCtxt<'tcx>>>(&self, val: T) -> T {
         debug!(
             "shift_vars(val={:?}, binders_passed={:?}, has_escaping_bound_vars={:?})",
             val,
diff --git a/compiler/rustc_middle/src/ty/trait_def.rs b/compiler/rustc_middle/src/ty/trait_def.rs
index a4a82bf247d..233c0df2d3c 100644
--- a/compiler/rustc_middle/src/ty/trait_def.rs
+++ b/compiler/rustc_middle/src/ty/trait_def.rs
@@ -1,6 +1,6 @@
 use crate::traits::specialization_graph;
 use crate::ty::fast_reject::{self, SimplifiedType, TreatParams};
-use crate::ty::visit::TypeVisitable;
+use crate::ty::visit::TypeVisitableExt;
 use crate::ty::{Ident, Ty, TyCtxt};
 use hir::def_id::LOCAL_CRATE;
 use rustc_hir as hir;
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs
index ca46cf29919..2ac3adda80b 100644
--- a/compiler/rustc_middle/src/ty/util.rs
+++ b/compiler/rustc_middle/src/ty/util.rs
@@ -4,8 +4,8 @@ use crate::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use crate::mir;
 use crate::ty::layout::IntegerExt;
 use crate::ty::{
-    self, ir::TypeFolder, DefIdTree, FallibleTypeFolder, ToPredicate, Ty, TyCtxt, TypeFoldable,
-    TypeSuperFoldable,
+    self, DefIdTree, FallibleTypeFolder, ToPredicate, Ty, TyCtxt, TypeFoldable, TypeFolder,
+    TypeSuperFoldable, TypeVisitableExt,
 };
 use crate::ty::{GenericArgKind, SubstsRef};
 use rustc_apfloat::Float as _;
@@ -1349,8 +1349,8 @@ pub fn fold_list<'tcx, F, T>(
     intern: impl FnOnce(TyCtxt<'tcx>, &[T]) -> &'tcx ty::List<T>,
 ) -> Result<&'tcx ty::List<T>, F::Error>
 where
-    F: FallibleTypeFolder<'tcx>,
-    T: TypeFoldable<'tcx> + PartialEq + Copy,
+    F: FallibleTypeFolder<TyCtxt<'tcx>>,
+    T: TypeFoldable<TyCtxt<'tcx>> + PartialEq + Copy,
 {
     let mut iter = list.iter();
     // Look for the first element that changed
diff --git a/compiler/rustc_middle/src/ty/visit.rs b/compiler/rustc_middle/src/ty/visit.rs
index 8a93b59900e..6814cadb9a8 100644
--- a/compiler/rustc_middle/src/ty/visit.rs
+++ b/compiler/rustc_middle/src/ty/visit.rs
@@ -5,15 +5,9 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::sso::SsoHashSet;
 use std::ops::ControlFlow;
 
-pub trait TypeVisitable<'tcx> = ir::TypeVisitable<TyCtxt<'tcx>> + TypeVisitableExt<'tcx>;
-pub trait TypeSuperVisitable<'tcx> = ir::TypeSuperVisitable<TyCtxt<'tcx>>;
-pub trait TypeVisitor<'tcx> = ir::TypeVisitor<TyCtxt<'tcx>>;
+pub use rustc_type_ir::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitor};
 
-pub mod ir {
-    pub use rustc_type_ir::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitor};
-}
-
-pub trait TypeVisitableExt<'tcx>: ir::TypeVisitable<TyCtxt<'tcx>> {
+pub trait TypeVisitableExt<'tcx>: TypeVisitable<TyCtxt<'tcx>> {
     /// Returns `true` if `self` has any late-bound regions that are either
     /// bound by `binder` or bound by some binder outside of `binder`.
     /// If `binder` is `ty::INNERMOST`, this indicates whether
@@ -135,7 +129,7 @@ pub trait TypeVisitableExt<'tcx>: ir::TypeVisitable<TyCtxt<'tcx>> {
     }
 }
 
-impl<'tcx, T: ir::TypeVisitable<TyCtxt<'tcx>>> TypeVisitableExt<'tcx> for T {}
+impl<'tcx, T: TypeVisitable<TyCtxt<'tcx>>> TypeVisitableExt<'tcx> for T {}
 
 ///////////////////////////////////////////////////////////////////////////
 // Region folder
@@ -144,7 +138,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Invoke `callback` on every region appearing free in `value`.
     pub fn for_each_free_region(
         self,
-        value: &impl TypeVisitable<'tcx>,
+        value: &impl TypeVisitable<TyCtxt<'tcx>>,
         mut callback: impl FnMut(ty::Region<'tcx>),
     ) {
         self.any_free_region_meets(value, |r| {
@@ -156,7 +150,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Returns `true` if `callback` returns true for every region appearing free in `value`.
     pub fn all_free_regions_meet(
         self,
-        value: &impl TypeVisitable<'tcx>,
+        value: &impl TypeVisitable<TyCtxt<'tcx>>,
         mut callback: impl FnMut(ty::Region<'tcx>) -> bool,
     ) -> bool {
         !self.any_free_region_meets(value, |r| !callback(r))
@@ -165,7 +159,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Returns `true` if `callback` returns true for some region appearing free in `value`.
     pub fn any_free_region_meets(
         self,
-        value: &impl TypeVisitable<'tcx>,
+        value: &impl TypeVisitable<TyCtxt<'tcx>>,
         callback: impl FnMut(ty::Region<'tcx>) -> bool,
     ) -> bool {
         struct RegionVisitor<F> {
@@ -190,13 +184,13 @@ impl<'tcx> TyCtxt<'tcx> {
             callback: F,
         }
 
-        impl<'tcx, F> ir::TypeVisitor<TyCtxt<'tcx>> for RegionVisitor<F>
+        impl<'tcx, F> TypeVisitor<TyCtxt<'tcx>> for RegionVisitor<F>
         where
             F: FnMut(ty::Region<'tcx>) -> bool,
         {
             type BreakTy = ();
 
-            fn visit_binder<T: TypeVisitable<'tcx>>(
+            fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(
                 &mut self,
                 t: &Binder<'tcx, T>,
             ) -> ControlFlow<Self::BreakTy> {
@@ -243,7 +237,7 @@ impl<'tcx> TyCtxt<'tcx> {
         value: &Binder<'tcx, T>,
     ) -> FxHashSet<ty::BoundRegionKind>
     where
-        T: TypeVisitable<'tcx>,
+        T: TypeVisitable<TyCtxt<'tcx>>,
     {
         self.collect_late_bound_regions(value, true)
     }
@@ -254,7 +248,7 @@ impl<'tcx> TyCtxt<'tcx> {
         value: &Binder<'tcx, T>,
     ) -> FxHashSet<ty::BoundRegionKind>
     where
-        T: TypeVisitable<'tcx>,
+        T: TypeVisitable<TyCtxt<'tcx>>,
     {
         self.collect_late_bound_regions(value, false)
     }
@@ -265,7 +259,7 @@ impl<'tcx> TyCtxt<'tcx> {
         just_constraint: bool,
     ) -> FxHashSet<ty::BoundRegionKind>
     where
-        T: TypeVisitable<'tcx>,
+        T: TypeVisitable<TyCtxt<'tcx>>,
     {
         let mut collector = LateBoundRegionsCollector::new(just_constraint);
         let result = value.as_ref().skip_binder().visit_with(&mut collector);
@@ -292,10 +286,10 @@ impl<'tcx> ValidateBoundVars<'tcx> {
     }
 }
 
-impl<'tcx> ir::TypeVisitor<TyCtxt<'tcx>> for ValidateBoundVars<'tcx> {
+impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for ValidateBoundVars<'tcx> {
     type BreakTy = ();
 
-    fn visit_binder<T: TypeVisitable<'tcx>>(
+    fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(
         &mut self,
         t: &Binder<'tcx, T>,
     ) -> ControlFlow<Self::BreakTy> {
@@ -404,10 +398,10 @@ struct HasEscapingVarsVisitor {
     outer_index: ty::DebruijnIndex,
 }
 
-impl<'tcx> ir::TypeVisitor<TyCtxt<'tcx>> for HasEscapingVarsVisitor {
+impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for HasEscapingVarsVisitor {
     type BreakTy = FoundEscapingVars;
 
-    fn visit_binder<T: TypeVisitable<'tcx>>(
+    fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(
         &mut self,
         t: &Binder<'tcx, T>,
     ) -> ControlFlow<Self::BreakTy> {
@@ -481,7 +475,7 @@ impl std::fmt::Debug for HasTypeFlagsVisitor {
     }
 }
 
-impl<'tcx> ir::TypeVisitor<TyCtxt<'tcx>> for HasTypeFlagsVisitor {
+impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for HasTypeFlagsVisitor {
     type BreakTy = FoundFlags;
 
     #[inline]
@@ -551,8 +545,8 @@ impl LateBoundRegionsCollector {
     }
 }
 
-impl<'tcx> ir::TypeVisitor<TyCtxt<'tcx>> for LateBoundRegionsCollector {
-    fn visit_binder<T: TypeVisitable<'tcx>>(
+impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for LateBoundRegionsCollector {
+    fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(
         &mut self,
         t: &Binder<'tcx, T>,
     ) -> ControlFlow<Self::BreakTy> {
@@ -613,7 +607,7 @@ impl MaxUniverse {
     }
 }
 
-impl<'tcx> ir::TypeVisitor<TyCtxt<'tcx>> for MaxUniverse {
+impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for MaxUniverse {
     fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
         if let ty::Placeholder(placeholder) = t.kind() {
             self.max_universe = ty::UniverseIndex::from_u32(
diff --git a/compiler/rustc_mir_build/src/build/matches/util.rs b/compiler/rustc_mir_build/src/build/matches/util.rs
index fbe08a7bd24..c34105174ef 100644
--- a/compiler/rustc_mir_build/src/build/matches/util.rs
+++ b/compiler/rustc_mir_build/src/build/matches/util.rs
@@ -5,7 +5,7 @@ use crate::build::Builder;
 use rustc_middle::mir::*;
 use rustc_middle::thir::*;
 use rustc_middle::ty;
-use rustc_middle::ty::TypeVisitable;
+use rustc_middle::ty::TypeVisitableExt;
 use smallvec::SmallVec;
 
 impl<'a, 'tcx> Builder<'a, 'tcx> {
diff --git a/compiler/rustc_mir_build/src/build/mod.rs b/compiler/rustc_mir_build/src/build/mod.rs
index 933b1158fa6..53bef1eb772 100644
--- a/compiler/rustc_mir_build/src/build/mod.rs
+++ b/compiler/rustc_mir_build/src/build/mod.rs
@@ -20,7 +20,7 @@ use rustc_middle::mir::*;
 use rustc_middle::thir::{
     self, BindingMode, Expr, ExprId, LintLevel, LocalVarId, Param, ParamId, PatKind, Thir,
 };
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable, TypeckResults};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt, TypeckResults};
 use rustc_span::symbol::sym;
 use rustc_span::Span;
 use rustc_span::Symbol;
diff --git a/compiler/rustc_mir_transform/src/const_prop.rs b/compiler/rustc_mir_transform/src/const_prop.rs
index cff3da720fc..6b2eefce24d 100644
--- a/compiler/rustc_mir_transform/src/const_prop.rs
+++ b/compiler/rustc_mir_transform/src/const_prop.rs
@@ -16,7 +16,7 @@ use rustc_middle::mir::visit::{
 use rustc_middle::mir::*;
 use rustc_middle::ty::layout::{LayoutError, LayoutOf, LayoutOfHelpers, TyAndLayout};
 use rustc_middle::ty::InternalSubsts;
-use rustc_middle::ty::{self, ConstKind, Instance, ParamEnv, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, ConstKind, Instance, ParamEnv, Ty, TyCtxt, TypeVisitableExt};
 use rustc_span::{def_id::DefId, Span};
 use rustc_target::abi::{self, Align, HasDataLayout, Size, TargetDataLayout};
 use rustc_target::spec::abi::Abi as CallAbi;
diff --git a/compiler/rustc_mir_transform/src/const_prop_lint.rs b/compiler/rustc_mir_transform/src/const_prop_lint.rs
index be41d611fe4..6c1980ff3ad 100644
--- a/compiler/rustc_mir_transform/src/const_prop_lint.rs
+++ b/compiler/rustc_mir_transform/src/const_prop_lint.rs
@@ -21,7 +21,9 @@ use rustc_middle::mir::{
 };
 use rustc_middle::ty::layout::{LayoutError, LayoutOf, LayoutOfHelpers, TyAndLayout};
 use rustc_middle::ty::InternalSubsts;
-use rustc_middle::ty::{self, ConstInt, Instance, ParamEnv, ScalarInt, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{
+    self, ConstInt, Instance, ParamEnv, ScalarInt, Ty, TyCtxt, TypeVisitableExt,
+};
 use rustc_session::lint;
 use rustc_span::Span;
 use rustc_target::abi::{HasDataLayout, Size, TargetDataLayout};
diff --git a/compiler/rustc_mir_transform/src/inline/cycle.rs b/compiler/rustc_mir_transform/src/inline/cycle.rs
index b027f94925d..792457c80b0 100644
--- a/compiler/rustc_mir_transform/src/inline/cycle.rs
+++ b/compiler/rustc_mir_transform/src/inline/cycle.rs
@@ -2,7 +2,7 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_middle::mir::TerminatorKind;
-use rustc_middle::ty::TypeVisitable;
+use rustc_middle::ty::TypeVisitableExt;
 use rustc_middle::ty::{self, subst::SubstsRef, InstanceDef, TyCtxt};
 use rustc_session::Limit;
 
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
index 45cd4024c9f..bdd1e8fb98f 100644
--- a/compiler/rustc_mir_transform/src/lib.rs
+++ b/compiler/rustc_mir_transform/src/lib.rs
@@ -35,7 +35,7 @@ use rustc_middle::mir::{
     TerminatorKind,
 };
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::{self, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, TyCtxt, TypeVisitableExt};
 use rustc_span::sym;
 
 #[macro_use]
diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs
index 55a9f912e08..ff409a80716 100644
--- a/compiler/rustc_monomorphize/src/collector.rs
+++ b/compiler/rustc_monomorphize/src/collector.rs
@@ -189,7 +189,9 @@ use rustc_middle::ty::adjustment::{CustomCoerceUnsized, PointerCast};
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::query::TyCtxtAt;
 use rustc_middle::ty::subst::{GenericArgKind, InternalSubsts};
-use rustc_middle::ty::{self, GenericParamDefKind, Instance, Ty, TyCtxt, TypeFoldable, VtblEntry};
+use rustc_middle::ty::{
+    self, GenericParamDefKind, Instance, Ty, TyCtxt, TypeFoldable, TypeVisitableExt, VtblEntry,
+};
 use rustc_middle::{middle::codegen_fn_attrs::CodegenFnAttrFlags, mir::visit::TyContext};
 use rustc_session::config::EntryFnType;
 use rustc_session::lint::builtin::LARGE_ASSIGNMENTS;
@@ -658,7 +660,7 @@ struct MirNeighborCollector<'a, 'tcx> {
 impl<'a, 'tcx> MirNeighborCollector<'a, 'tcx> {
     pub fn monomorphize<T>(&self, value: T) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         debug!("monomorphize: self.instance={:?}", self.instance);
         self.instance.subst_mir_and_normalize_erasing_regions(
diff --git a/compiler/rustc_monomorphize/src/partitioning/default.rs b/compiler/rustc_monomorphize/src/partitioning/default.rs
index 62bafb981e7..2c56edd89bc 100644
--- a/compiler/rustc_monomorphize/src/partitioning/default.rs
+++ b/compiler/rustc_monomorphize/src/partitioning/default.rs
@@ -9,7 +9,7 @@ use rustc_middle::middle::exported_symbols::{SymbolExportInfo, SymbolExportLevel
 use rustc_middle::mir::mono::{CodegenUnit, CodegenUnitNameBuilder, Linkage, Visibility};
 use rustc_middle::mir::mono::{InstantiationMode, MonoItem};
 use rustc_middle::ty::print::characteristic_def_id_of_type;
-use rustc_middle::ty::{self, visit::TypeVisitable, DefIdTree, InstanceDef, TyCtxt};
+use rustc_middle::ty::{self, visit::TypeVisitableExt, DefIdTree, InstanceDef, TyCtxt};
 use rustc_span::symbol::Symbol;
 
 use super::PartitioningCx;
diff --git a/compiler/rustc_monomorphize/src/polymorphize.rs b/compiler/rustc_monomorphize/src/polymorphize.rs
index 207ad332c22..b7c3dbcc091 100644
--- a/compiler/rustc_monomorphize/src/polymorphize.rs
+++ b/compiler/rustc_monomorphize/src/polymorphize.rs
@@ -15,7 +15,7 @@ use rustc_middle::ty::{
     self,
     query::Providers,
     subst::SubstsRef,
-    visit::{ir::TypeVisitor, TypeSuperVisitable, TypeVisitable},
+    visit::{TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor},
     Const, Ty, TyCtxt, UnusedGenericParams,
 };
 use rustc_span::symbol::sym;
diff --git a/compiler/rustc_privacy/src/lib.rs b/compiler/rustc_privacy/src/lib.rs
index 9e856bb8a08..b383bd27737 100644
--- a/compiler/rustc_privacy/src/lib.rs
+++ b/compiler/rustc_privacy/src/lib.rs
@@ -30,7 +30,7 @@ use rustc_middle::span_bug;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::subst::InternalSubsts;
 use rustc_middle::ty::{self, Const, DefIdTree, GenericParamDefKind};
-use rustc_middle::ty::{ir::TypeVisitor, TraitRef, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable};
+use rustc_middle::ty::{TraitRef, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor};
 use rustc_session::lint;
 use rustc_span::hygiene::Transparency;
 use rustc_span::symbol::{kw, sym, Ident};
@@ -85,7 +85,10 @@ trait DefIdVisitor<'tcx> {
             dummy: Default::default(),
         }
     }
-    fn visit(&mut self, ty_fragment: impl TypeVisitable<'tcx>) -> ControlFlow<Self::BreakTy> {
+    fn visit(
+        &mut self,
+        ty_fragment: impl TypeVisitable<TyCtxt<'tcx>>,
+    ) -> ControlFlow<Self::BreakTy> {
         ty_fragment.visit_with(&mut self.skeleton())
     }
     fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> ControlFlow<Self::BreakTy> {
diff --git a/compiler/rustc_symbol_mangling/src/legacy.rs b/compiler/rustc_symbol_mangling/src/legacy.rs
index 744e8a4320e..2368468c891 100644
--- a/compiler/rustc_symbol_mangling/src/legacy.rs
+++ b/compiler/rustc_symbol_mangling/src/legacy.rs
@@ -3,7 +3,7 @@ use rustc_hir::def_id::CrateNum;
 use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData};
 use rustc_middle::ty::print::{PrettyPrinter, Print, Printer};
 use rustc_middle::ty::subst::{GenericArg, GenericArgKind};
-use rustc_middle::ty::{self, Instance, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, Instance, Ty, TyCtxt, TypeVisitableExt};
 use rustc_middle::util::common::record_time;
 
 use std::fmt::{self, Write};
diff --git a/compiler/rustc_symbol_mangling/src/v0.rs b/compiler/rustc_symbol_mangling/src/v0.rs
index d53f0cea6b5..2f20d42139c 100644
--- a/compiler/rustc_symbol_mangling/src/v0.rs
+++ b/compiler/rustc_symbol_mangling/src/v0.rs
@@ -8,7 +8,8 @@ use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData};
 use rustc_middle::ty::layout::IntegerExt;
 use rustc_middle::ty::print::{Print, Printer};
 use rustc_middle::ty::{
-    self, EarlyBinder, FloatTy, Instance, IntTy, Ty, TyCtxt, TypeVisitable, UintTy,
+    self, EarlyBinder, FloatTy, Instance, IntTy, Ty, TyCtxt, TypeVisitable, TypeVisitableExt,
+    UintTy,
 };
 use rustc_middle::ty::{GenericArg, GenericArgKind};
 use rustc_span::symbol::kw;
@@ -204,7 +205,7 @@ impl<'tcx> SymbolMangler<'tcx> {
         print_value: impl FnOnce(&'a mut Self, &T) -> Result<&'a mut Self, !>,
     ) -> Result<&'a mut Self, !>
     where
-        T: TypeVisitable<'tcx>,
+        T: TypeVisitable<TyCtxt<'tcx>>,
     {
         // FIXME(non-lifetime-binders): What to do here?
         let regions = if value.has_late_bound_regions() {
diff --git a/compiler/rustc_trait_selection/src/infer.rs b/compiler/rustc_trait_selection/src/infer.rs
index c0bfe152a1e..015029b7ac4 100644
--- a/compiler/rustc_trait_selection/src/infer.rs
+++ b/compiler/rustc_trait_selection/src/infer.rs
@@ -6,7 +6,7 @@ use rustc_hir::lang_items::LangItem;
 use rustc_middle::arena::ArenaAllocatable;
 use rustc_middle::infer::canonical::{Canonical, CanonicalQueryResponse, QueryResponse};
 use rustc_middle::traits::query::Fallible;
-use rustc_middle::ty::{self, Ty, TypeFoldable};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable, TypeVisitableExt};
 use rustc_middle::ty::{GenericArg, ToPredicate};
 use rustc_span::{Span, DUMMY_SP};
 
@@ -104,8 +104,8 @@ pub trait InferCtxtBuilderExt<'tcx> {
         operation: impl FnOnce(&ObligationCtxt<'_, 'tcx>, K) -> Fallible<R>,
     ) -> Fallible<CanonicalQueryResponse<'tcx, R>>
     where
-        K: TypeFoldable<'tcx>,
-        R: Debug + TypeFoldable<'tcx>,
+        K: TypeFoldable<TyCtxt<'tcx>>,
+        R: Debug + TypeFoldable<TyCtxt<'tcx>>,
         Canonical<'tcx, QueryResponse<'tcx, R>>: ArenaAllocatable<'tcx>;
 }
 
@@ -125,15 +125,15 @@ impl<'tcx> InferCtxtBuilderExt<'tcx> for InferCtxtBuilder<'tcx> {
     /// In part because we would need a `for<'tcx>` sort of
     /// bound for the closure and in part because it is convenient to
     /// have `'tcx` be free on this function so that we can talk about
-    /// `K: TypeFoldable<'tcx>`.)
+    /// `K: TypeFoldable<TyCtxt<'tcx>>`.)
     fn enter_canonical_trait_query<K, R>(
         &mut self,
         canonical_key: &Canonical<'tcx, K>,
         operation: impl FnOnce(&ObligationCtxt<'_, 'tcx>, K) -> Fallible<R>,
     ) -> Fallible<CanonicalQueryResponse<'tcx, R>>
     where
-        K: TypeFoldable<'tcx>,
-        R: Debug + TypeFoldable<'tcx>,
+        K: TypeFoldable<TyCtxt<'tcx>>,
+        R: Debug + TypeFoldable<TyCtxt<'tcx>>,
         Canonical<'tcx, QueryResponse<'tcx, R>>: ArenaAllocatable<'tcx>,
     {
         let (infcx, key, canonical_inference_vars) =
diff --git a/compiler/rustc_trait_selection/src/solve/assembly.rs b/compiler/rustc_trait_selection/src/solve/assembly.rs
index d55aebf1a26..6172a9539f6 100644
--- a/compiler/rustc_trait_selection/src/solve/assembly.rs
+++ b/compiler/rustc_trait_selection/src/solve/assembly.rs
@@ -82,7 +82,7 @@ pub(super) enum CandidateSource {
 }
 
 /// Methods used to assemble candidates for either trait or projection goals.
-pub(super) trait GoalKind<'tcx>: TypeFoldable<'tcx> + Copy + Eq {
+pub(super) trait GoalKind<'tcx>: TypeFoldable<TyCtxt<'tcx>> + Copy + Eq {
     fn self_ty(self) -> Ty<'tcx>;
 
     fn with_self_ty(self, tcx: TyCtxt<'tcx>, self_ty: Ty<'tcx>) -> Self;
diff --git a/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs b/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs
index 67addd732d0..c8097e81953 100644
--- a/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs
+++ b/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs
@@ -6,7 +6,10 @@ use rustc_infer::infer::{InferCtxt, InferOk, LateBoundRegionConversionTime};
 use rustc_infer::traits::query::NoSolution;
 use rustc_infer::traits::ObligationCause;
 use rustc_middle::infer::unify_key::{ConstVariableOrigin, ConstVariableOriginKind};
-use rustc_middle::ty::{self, ir::TypeVisitor, Ty, TyCtxt, TypeFoldable, TypeSuperVisitable};
+use rustc_middle::ty::{
+    self, Ty, TyCtxt, TypeFoldable, TypeSuperVisitable, TypeVisitable, TypeVisitableExt,
+    TypeVisitor,
+};
 use rustc_span::DUMMY_SP;
 use std::ops::ControlFlow;
 
@@ -137,7 +140,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             })
     }
 
-    pub(super) fn instantiate_binder_with_infer<T: TypeFoldable<'tcx> + Copy>(
+    pub(super) fn instantiate_binder_with_infer<T: TypeFoldable<TyCtxt<'tcx>> + Copy>(
         &self,
         value: ty::Binder<'tcx, T>,
     ) -> T {
@@ -148,7 +151,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         )
     }
 
-    pub(super) fn instantiate_binder_with_placeholders<T: TypeFoldable<'tcx> + Copy>(
+    pub(super) fn instantiate_binder_with_placeholders<T: TypeFoldable<TyCtxt<'tcx>> + Copy>(
         &self,
         value: ty::Binder<'tcx, T>,
     ) -> T {
@@ -157,7 +160,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
 
     pub(super) fn resolve_vars_if_possible<T>(&self, value: T) -> T
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         self.infcx.resolve_vars_if_possible(value)
     }
diff --git a/compiler/rustc_trait_selection/src/solve/project_goals.rs b/compiler/rustc_trait_selection/src/solve/project_goals.rs
index 9f83bfa1ccb..08c24ce13a5 100644
--- a/compiler/rustc_trait_selection/src/solve/project_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/project_goals.rs
@@ -14,7 +14,7 @@ use rustc_infer::traits::Reveal;
 use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams};
 use rustc_middle::ty::ProjectionPredicate;
 use rustc_middle::ty::{self, Ty, TyCtxt};
-use rustc_middle::ty::{ToPredicate, TypeVisitable};
+use rustc_middle::ty::{ToPredicate, TypeVisitableExt};
 use rustc_span::{sym, DUMMY_SP};
 use std::iter;
 
diff --git a/compiler/rustc_trait_selection/src/solve/trait_goals.rs b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
index 6d1381bbf0c..aff79739d45 100644
--- a/compiler/rustc_trait_selection/src/solve/trait_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
@@ -10,7 +10,7 @@ use rustc_infer::traits::query::NoSolution;
 use rustc_infer::traits::util::supertraits;
 use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams};
 use rustc_middle::ty::{self, ToPredicate, Ty, TyCtxt};
-use rustc_middle::ty::{TraitPredicate, TypeVisitable};
+use rustc_middle::ty::{TraitPredicate, TypeVisitableExt};
 use rustc_span::DUMMY_SP;
 
 pub mod structural_traits;
diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
index 9776cc57af8..6f2b0856d51 100644
--- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs
+++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
@@ -8,9 +8,8 @@ use crate::infer::region_constraints::{Constraint, RegionConstraintData};
 use crate::infer::InferCtxt;
 use crate::traits::project::ProjectAndUnifyResult;
 use rustc_middle::mir::interpret::ErrorHandled;
-use rustc_middle::ty::fold::{ir::TypeFolder, TypeSuperFoldable};
-#[cfg(not(bootstrap))]
-use rustc_middle::ty::visit::TypeVisitable;
+use rustc_middle::ty::fold::{TypeFolder, TypeSuperFoldable};
+use rustc_middle::ty::visit::TypeVisitableExt;
 use rustc_middle::ty::{ImplPolarity, Region, RegionVid};
 
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
diff --git a/compiler/rustc_trait_selection/src/traits/chalk_fulfill.rs b/compiler/rustc_trait_selection/src/traits/chalk_fulfill.rs
index e26bef0b8b7..b42a49eb47b 100644
--- a/compiler/rustc_trait_selection/src/traits/chalk_fulfill.rs
+++ b/compiler/rustc_trait_selection/src/traits/chalk_fulfill.rs
@@ -8,7 +8,7 @@ use crate::traits::{
     SelectionError, TraitEngine,
 };
 use rustc_data_structures::fx::FxIndexSet;
-use rustc_middle::ty::TypeVisitable;
+use rustc_middle::ty::TypeVisitableExt;
 
 pub struct FulfillmentContext<'tcx> {
     obligations: FxIndexSet<PredicateObligation<'tcx>>,
diff --git a/compiler/rustc_trait_selection/src/traits/coherence.rs b/compiler/rustc_trait_selection/src/traits/coherence.rs
index 44369670f5f..6b688c322c7 100644
--- a/compiler/rustc_trait_selection/src/traits/coherence.rs
+++ b/compiler/rustc_trait_selection/src/traits/coherence.rs
@@ -21,8 +21,8 @@ use rustc_infer::infer::{DefiningAnchor, InferCtxt, TyCtxtInferExt};
 use rustc_infer::traits::util;
 use rustc_middle::traits::specialization_graph::OverlapMode;
 use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams};
-use rustc_middle::ty::visit::TypeVisitable;
-use rustc_middle::ty::{self, ir::TypeVisitor, ImplSubject, Ty, TyCtxt};
+use rustc_middle::ty::visit::{TypeVisitable, TypeVisitableExt};
+use rustc_middle::ty::{self, ImplSubject, Ty, TyCtxt, TypeVisitor};
 use rustc_span::symbol::sym;
 use rustc_span::DUMMY_SP;
 use std::fmt::Debug;
diff --git a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs
index dd9b5b534d7..345e84990ed 100644
--- a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs
+++ b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs
@@ -14,7 +14,7 @@ use rustc_middle::mir::interpret::ErrorHandled;
 
 use rustc_middle::traits::ObligationCause;
 use rustc_middle::ty::abstract_const::NotConstEvaluatable;
-use rustc_middle::ty::{self, ir::TypeVisitor, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, TyCtxt, TypeVisitable, TypeVisitableExt, TypeVisitor};
 
 use rustc_span::Span;
 use std::ops::ControlFlow;
diff --git a/compiler/rustc_trait_selection/src/traits/engine.rs b/compiler/rustc_trait_selection/src/traits/engine.rs
index 4a7f08a35bc..b20636174ee 100644
--- a/compiler/rustc_trait_selection/src/traits/engine.rs
+++ b/compiler/rustc_trait_selection/src/traits/engine.rs
@@ -104,7 +104,7 @@ impl<'a, 'tcx> ObligationCtxt<'a, 'tcx> {
         });
     }
 
-    pub fn normalize<T: TypeFoldable<'tcx>>(
+    pub fn normalize<T: TypeFoldable<TyCtxt<'tcx>>>(
         &self,
         cause: &ObligationCause<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
@@ -220,7 +220,7 @@ impl<'a, 'tcx> ObligationCtxt<'a, 'tcx> {
         answer: T,
     ) -> Fallible<CanonicalQueryResponse<'tcx, T>>
     where
-        T: Debug + TypeFoldable<'tcx>,
+        T: Debug + TypeFoldable<TyCtxt<'tcx>>,
         Canonical<'tcx, QueryResponse<'tcx, T>>: ArenaAllocatable<'tcx>,
     {
         self.infcx.make_canonicalized_query_response(
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index a32ab16263a..a844a1494e2 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -34,10 +34,11 @@ use rustc_infer::infer::{InferOk, TypeTrace};
 use rustc_middle::traits::select::OverflowError;
 use rustc_middle::ty::abstract_const::NotConstEvaluatable;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
-use rustc_middle::ty::fold::{ir::TypeFolder, TypeSuperFoldable};
+use rustc_middle::ty::fold::{TypeFolder, TypeSuperFoldable};
 use rustc_middle::ty::print::{with_forced_trimmed_paths, FmtPrinter, Print};
 use rustc_middle::ty::{
     self, SubtypePredicate, ToPolyTraitRef, ToPredicate, TraitRef, Ty, TyCtxt, TypeFoldable,
+    TypeVisitable, TypeVisitableExt,
 };
 use rustc_session::config::TraitSolver;
 use rustc_session::Limit;
@@ -108,7 +109,7 @@ pub trait TypeErrCtxtExt<'tcx> {
     ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed>
     where
         T: fmt::Display
-            + TypeFoldable<'tcx>
+            + TypeFoldable<TyCtxt<'tcx>>
             + Print<'tcx, FmtPrinter<'tcx, 'tcx>, Output = FmtPrinter<'tcx, 'tcx>>,
         <T as Print<'tcx, FmtPrinter<'tcx, 'tcx>>>::Error: std::fmt::Debug;
 
@@ -121,7 +122,7 @@ pub trait TypeErrCtxtExt<'tcx> {
     ) -> !
     where
         T: fmt::Display
-            + TypeFoldable<'tcx>
+            + TypeFoldable<TyCtxt<'tcx>>
             + Print<'tcx, FmtPrinter<'tcx, 'tcx>, Output = FmtPrinter<'tcx, 'tcx>>,
         <T as Print<'tcx, FmtPrinter<'tcx, 'tcx>>>::Error: std::fmt::Debug;
 
@@ -491,7 +492,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
     ) -> !
     where
         T: fmt::Display
-            + TypeFoldable<'tcx>
+            + TypeFoldable<TyCtxt<'tcx>>
             + Print<'tcx, FmtPrinter<'tcx, 'tcx>, Output = FmtPrinter<'tcx, 'tcx>>,
         <T as Print<'tcx, FmtPrinter<'tcx, 'tcx>>>::Error: std::fmt::Debug,
     {
@@ -511,7 +512,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
     ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed>
     where
         T: fmt::Display
-            + TypeFoldable<'tcx>
+            + TypeFoldable<TyCtxt<'tcx>>
             + Print<'tcx, FmtPrinter<'tcx, 'tcx>, Output = FmtPrinter<'tcx, 'tcx>>,
         <T as Print<'tcx, FmtPrinter<'tcx, 'tcx>>>::Error: std::fmt::Debug,
     {
@@ -2970,7 +2971,7 @@ impl ArgKind {
 
 struct HasNumericInferVisitor;
 
-impl<'tcx> ty::ir::TypeVisitor<TyCtxt<'tcx>> for HasNumericInferVisitor {
+impl<'tcx> ty::TypeVisitor<TyCtxt<'tcx>> for HasNumericInferVisitor {
     type BreakTy = ();
 
     fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index 824264c21d0..84945ff28fe 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -30,10 +30,10 @@ use rustc_middle::hir::map;
 use rustc_middle::ty::error::TypeError::{self, Sorts};
 use rustc_middle::ty::relate::TypeRelation;
 use rustc_middle::ty::{
-    self, ir::TypeFolder, suggest_arbitrary_trait_bound, suggest_constraining_type_param, AdtKind,
-    DefIdTree, GeneratorDiagnosticData, GeneratorInteriorTypeCause, Infer, InferTy, InternalSubsts,
-    IsSuggestable, ToPredicate, Ty, TyCtxt, TypeAndMut, TypeFoldable, TypeSuperFoldable,
-    TypeckResults,
+    self, suggest_arbitrary_trait_bound, suggest_constraining_type_param, AdtKind, DefIdTree,
+    GeneratorDiagnosticData, GeneratorInteriorTypeCause, Infer, InferTy, InternalSubsts,
+    IsSuggestable, ToPredicate, Ty, TyCtxt, TypeAndMut, TypeFoldable, TypeFolder,
+    TypeSuperFoldable, TypeVisitableExt, TypeckResults,
 };
 use rustc_span::def_id::LocalDefId;
 use rustc_span::symbol::{sym, Ident, Symbol};
diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs
index deeed930e50..da2416b9646 100644
--- a/compiler/rustc_trait_selection/src/traits/fulfill.rs
+++ b/compiler/rustc_trait_selection/src/traits/fulfill.rs
@@ -8,7 +8,7 @@ use rustc_middle::mir::interpret::ErrorHandled;
 use rustc_middle::ty::abstract_const::NotConstEvaluatable;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::subst::SubstsRef;
-use rustc_middle::ty::{self, Binder, Const, TypeVisitable};
+use rustc_middle::ty::{self, Binder, Const, TypeVisitableExt};
 use std::marker::PhantomData;
 
 use super::const_evaluatable;
diff --git a/compiler/rustc_trait_selection/src/traits/misc.rs b/compiler/rustc_trait_selection/src/traits/misc.rs
index de730773794..b94346b0956 100644
--- a/compiler/rustc_trait_selection/src/traits/misc.rs
+++ b/compiler/rustc_trait_selection/src/traits/misc.rs
@@ -8,7 +8,7 @@ use rustc_infer::infer::canonical::Canonical;
 use rustc_infer::infer::{RegionResolutionError, TyCtxtInferExt};
 use rustc_infer::traits::query::NoSolution;
 use rustc_infer::{infer::outlives::env::OutlivesEnvironment, traits::FulfillmentError};
-use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt, TypeVisitableExt};
 use rustc_span::DUMMY_SP;
 
 use super::outlives_bounds::InferCtxtExt;
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index 2d299486ee6..c8b233bfe26 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -27,7 +27,7 @@ use crate::traits::error_reporting::TypeErrCtxtExt as _;
 use crate::traits::query::evaluate_obligation::InferCtxtExt as _;
 use rustc_errors::ErrorGuaranteed;
 use rustc_middle::ty::fold::TypeFoldable;
-use rustc_middle::ty::visit::TypeVisitable;
+use rustc_middle::ty::visit::{TypeVisitable, TypeVisitableExt};
 use rustc_middle::ty::{self, DefIdTree, ToPredicate, Ty, TyCtxt, TypeSuperVisitable};
 use rustc_middle::ty::{InternalSubsts, SubstsRef};
 use rustc_span::def_id::{DefId, CRATE_DEF_ID};
@@ -141,7 +141,7 @@ pub fn type_known_to_meet_bound_modulo_regions<'tcx>(
 fn pred_known_to_hold_modulo_regions<'tcx>(
     infcx: &InferCtxt<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
-    pred: impl ToPredicate<'tcx> + TypeVisitable<'tcx>,
+    pred: impl ToPredicate<'tcx> + TypeVisitable<TyCtxt<'tcx>>,
     span: Span,
 ) -> bool {
     let has_non_region_infer = pred.has_non_region_infer();
@@ -371,7 +371,7 @@ pub fn fully_normalize<'tcx, T>(
     value: T,
 ) -> Result<T, Vec<FulfillmentError<'tcx>>>
 where
-    T: TypeFoldable<'tcx>,
+    T: TypeFoldable<TyCtxt<'tcx>>,
 {
     let ocx = ObligationCtxt::new(infcx);
     debug!(?value);
@@ -481,7 +481,7 @@ fn is_impossible_method(tcx: TyCtxt<'_>, (impl_def_id, trait_item_def_id): (DefI
         generics: &'tcx ty::Generics,
         trait_item_def_id: DefId,
     }
-    impl<'tcx> ty::ir::TypeVisitor<TyCtxt<'tcx>> for ReferencesOnlyParentGenerics<'tcx> {
+    impl<'tcx> ty::TypeVisitor<TyCtxt<'tcx>> for ReferencesOnlyParentGenerics<'tcx> {
         type BreakTy = ();
         fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
             // If this is a parameter from the trait item's own generics, then bail
diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs
index df1aeed941d..b87f75422ef 100644
--- a/compiler/rustc_trait_selection/src/traits/object_safety.rs
+++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs
@@ -19,7 +19,7 @@ use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_middle::ty::subst::{GenericArg, InternalSubsts};
 use rustc_middle::ty::{
-    self, ir::TypeVisitor, EarlyBinder, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable,
+    self, EarlyBinder, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor,
 };
 use rustc_middle::ty::{Predicate, ToPredicate};
 use rustc_session::lint::builtin::WHERE_CLAUSES_OBJECT_SAFETY;
@@ -790,7 +790,7 @@ fn receiver_is_dispatchable<'tcx>(
     infcx.predicate_must_hold_modulo_regions(&obligation)
 }
 
-fn contains_illegal_self_type_reference<'tcx, T: TypeVisitable<'tcx>>(
+fn contains_illegal_self_type_reference<'tcx, T: TypeVisitable<TyCtxt<'tcx>>>(
     tcx: TyCtxt<'tcx>,
     trait_def_id: DefId,
     value: T,
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index 9ccdeca842c..279725b16d8 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -30,8 +30,8 @@ use rustc_infer::infer::at::At;
 use rustc_infer::infer::resolve::OpportunisticRegionResolver;
 use rustc_infer::traits::ImplSourceBuiltinData;
 use rustc_middle::traits::select::OverflowError;
-use rustc_middle::ty::fold::{ir::TypeFolder, TypeFoldable, TypeSuperFoldable};
-use rustc_middle::ty::visit::{MaxUniverse, TypeVisitable};
+use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
+use rustc_middle::ty::visit::{MaxUniverse, TypeVisitable, TypeVisitableExt};
 use rustc_middle::ty::DefIdTree;
 use rustc_middle::ty::{self, Term, ToPredicate, Ty, TyCtxt};
 use rustc_span::symbol::sym;
@@ -53,11 +53,11 @@ pub trait NormalizeExt<'tcx> {
     ///
     /// This normalization should be used when the type contains inference variables or the
     /// projection may be fallible.
-    fn normalize<T: TypeFoldable<'tcx>>(&self, t: T) -> InferOk<'tcx, T>;
+    fn normalize<T: TypeFoldable<TyCtxt<'tcx>>>(&self, t: T) -> InferOk<'tcx, T>;
 }
 
 impl<'tcx> NormalizeExt<'tcx> for At<'_, 'tcx> {
-    fn normalize<T: TypeFoldable<'tcx>>(&self, value: T) -> InferOk<'tcx, T> {
+    fn normalize<T: TypeFoldable<TyCtxt<'tcx>>>(&self, value: T) -> InferOk<'tcx, T> {
         let mut selcx = SelectionContext::new(self.infcx);
         let Normalized { value, obligations } =
             normalize_with_depth(&mut selcx, self.param_env, self.cause.clone(), 0, value);
@@ -312,7 +312,7 @@ pub(crate) fn normalize_with_depth<'a, 'b, 'tcx, T>(
     value: T,
 ) -> Normalized<'tcx, T>
 where
-    T: TypeFoldable<'tcx>,
+    T: TypeFoldable<TyCtxt<'tcx>>,
 {
     let mut obligations = Vec::new();
     let value = normalize_with_depth_to(selcx, param_env, cause, depth, value, &mut obligations);
@@ -329,7 +329,7 @@ pub(crate) fn normalize_with_depth_to<'a, 'b, 'tcx, T>(
     obligations: &mut Vec<PredicateObligation<'tcx>>,
 ) -> T
 where
-    T: TypeFoldable<'tcx>,
+    T: TypeFoldable<TyCtxt<'tcx>>,
 {
     debug!(obligations.len = obligations.len());
     let mut normalizer = AssocTypeNormalizer::new(selcx, param_env, cause, depth, obligations);
@@ -349,7 +349,7 @@ pub(crate) fn try_normalize_with_depth_to<'a, 'b, 'tcx, T>(
     obligations: &mut Vec<PredicateObligation<'tcx>>,
 ) -> T
 where
-    T: TypeFoldable<'tcx>,
+    T: TypeFoldable<TyCtxt<'tcx>>,
 {
     debug!(obligations.len = obligations.len());
     let mut normalizer = AssocTypeNormalizer::new_without_eager_inference_replacement(
@@ -365,7 +365,10 @@ where
     result
 }
 
-pub(crate) fn needs_normalization<'tcx, T: TypeVisitable<'tcx>>(value: &T, reveal: Reveal) -> bool {
+pub(crate) fn needs_normalization<'tcx, T: TypeVisitable<TyCtxt<'tcx>>>(
+    value: &T,
+    reveal: Reveal,
+) -> bool {
     match reveal {
         Reveal::UserFacing => value
             .has_type_flags(ty::TypeFlags::HAS_TY_PROJECTION | ty::TypeFlags::HAS_CT_PROJECTION),
@@ -427,7 +430,7 @@ impl<'a, 'b, 'tcx> AssocTypeNormalizer<'a, 'b, 'tcx> {
         }
     }
 
-    fn fold<T: TypeFoldable<'tcx>>(&mut self, value: T) -> T {
+    fn fold<T: TypeFoldable<TyCtxt<'tcx>>>(&mut self, value: T) -> T {
         let value = self.selcx.infcx.resolve_vars_if_possible(value);
         debug!(?value);
 
@@ -450,7 +453,7 @@ impl<'a, 'b, 'tcx> TypeFolder<TyCtxt<'tcx>> for AssocTypeNormalizer<'a, 'b, 'tcx
         self.selcx.tcx()
     }
 
-    fn fold_binder<T: TypeFoldable<'tcx>>(
+    fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
         &mut self,
         t: ty::Binder<'tcx, T>,
     ) -> ty::Binder<'tcx, T> {
@@ -669,7 +672,12 @@ pub struct BoundVarReplacer<'me, 'tcx> {
 ///
 /// FIXME(@lcnr): We may even consider experimenting with eagerly replacing bound vars during
 /// normalization as well, at which point this function will be unnecessary and can be removed.
-pub fn with_replaced_escaping_bound_vars<'a, 'tcx, T: TypeFoldable<'tcx>, R: TypeFoldable<'tcx>>(
+pub fn with_replaced_escaping_bound_vars<
+    'a,
+    'tcx,
+    T: TypeFoldable<TyCtxt<'tcx>>,
+    R: TypeFoldable<TyCtxt<'tcx>>,
+>(
     infcx: &'a InferCtxt<'tcx>,
     universe_indices: &'a mut Vec<Option<ty::UniverseIndex>>,
     value: T,
@@ -695,7 +703,7 @@ pub fn with_replaced_escaping_bound_vars<'a, 'tcx, T: TypeFoldable<'tcx>, R: Typ
 impl<'me, 'tcx> BoundVarReplacer<'me, 'tcx> {
     /// Returns `Some` if we *were* able to replace bound vars. If there are any bound vars that
     /// use a binding level above `universe_indices.len()`, we fail.
-    pub fn replace_bound_vars<T: TypeFoldable<'tcx>>(
+    pub fn replace_bound_vars<T: TypeFoldable<TyCtxt<'tcx>>>(
         infcx: &'me InferCtxt<'tcx>,
         universe_indices: &'me mut Vec<Option<ty::UniverseIndex>>,
         value: T,
@@ -742,7 +750,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for BoundVarReplacer<'_, 'tcx> {
         self.infcx.tcx
     }
 
-    fn fold_binder<T: TypeFoldable<'tcx>>(
+    fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
         &mut self,
         t: ty::Binder<'tcx, T>,
     ) -> ty::Binder<'tcx, T> {
@@ -823,7 +831,7 @@ pub struct PlaceholderReplacer<'me, 'tcx> {
 }
 
 impl<'me, 'tcx> PlaceholderReplacer<'me, 'tcx> {
-    pub fn replace_placeholders<T: TypeFoldable<'tcx>>(
+    pub fn replace_placeholders<T: TypeFoldable<TyCtxt<'tcx>>>(
         infcx: &'me InferCtxt<'tcx>,
         mapped_regions: BTreeMap<ty::PlaceholderRegion, ty::BoundRegion>,
         mapped_types: BTreeMap<ty::PlaceholderType, ty::BoundTy>,
@@ -848,7 +856,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for PlaceholderReplacer<'_, 'tcx> {
         self.infcx.tcx
     }
 
-    fn fold_binder<T: TypeFoldable<'tcx>>(
+    fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
         &mut self,
         t: ty::Binder<'tcx, T>,
     ) -> ty::Binder<'tcx, T> {
diff --git a/compiler/rustc_trait_selection/src/traits/query/normalize.rs b/compiler/rustc_trait_selection/src/traits/query/normalize.rs
index a266013b8fd..b0cec3ce7a3 100644
--- a/compiler/rustc_trait_selection/src/traits/query/normalize.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/normalize.rs
@@ -11,9 +11,9 @@ use crate::traits::{ObligationCause, PredicateObligation, Reveal};
 use rustc_data_structures::sso::SsoHashMap;
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_infer::traits::Normalized;
-use rustc_middle::ty::fold::{ir::FallibleTypeFolder, TypeFoldable, TypeSuperFoldable};
-use rustc_middle::ty::visit::{TypeSuperVisitable, TypeVisitable};
-use rustc_middle::ty::{self, ir::TypeVisitor, Ty, TyCtxt};
+use rustc_middle::ty::fold::{FallibleTypeFolder, TypeFoldable, TypeSuperFoldable};
+use rustc_middle::ty::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitableExt};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitor};
 use rustc_span::DUMMY_SP;
 
 use std::ops::ControlFlow;
@@ -32,7 +32,7 @@ pub trait QueryNormalizeExt<'tcx> {
     /// use [`TyCtxt::normalize_erasing_regions`], which wraps this procedure.
     fn query_normalize<T>(&self, value: T) -> Result<Normalized<'tcx, T>, NoSolution>
     where
-        T: TypeFoldable<'tcx>;
+        T: TypeFoldable<TyCtxt<'tcx>>;
 }
 
 impl<'cx, 'tcx> QueryNormalizeExt<'tcx> for At<'cx, 'tcx> {
@@ -51,7 +51,7 @@ impl<'cx, 'tcx> QueryNormalizeExt<'tcx> for At<'cx, 'tcx> {
     /// and other details are still "under development".
     fn query_normalize<T>(&self, value: T) -> Result<Normalized<'tcx, T>, NoSolution>
     where
-        T: TypeFoldable<'tcx>,
+        T: TypeFoldable<TyCtxt<'tcx>>,
     {
         debug!(
             "normalize::<{}>(value={:?}, param_env={:?}, cause={:?})",
@@ -116,7 +116,7 @@ struct MaxEscapingBoundVarVisitor {
 }
 
 impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for MaxEscapingBoundVarVisitor {
-    fn visit_binder<T: TypeVisitable<'tcx>>(
+    fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(
         &mut self,
         t: &ty::Binder<'tcx, T>,
     ) -> ControlFlow<Self::BreakTy> {
@@ -177,7 +177,7 @@ impl<'cx, 'tcx> FallibleTypeFolder<TyCtxt<'tcx>> for QueryNormalizer<'cx, 'tcx>
         self.infcx.tcx
     }
 
-    fn try_fold_binder<T: TypeFoldable<'tcx>>(
+    fn try_fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
         &mut self,
         t: ty::Binder<'tcx, T>,
     ) -> Result<ty::Binder<'tcx, T>, Self::Error> {
diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs
index 97002b461aa..9e8bc8bce9a 100644
--- a/compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs
@@ -54,8 +54,8 @@ pub struct TypeOpOutput<'tcx, Op: TypeOp<'tcx>> {
 /// which produces the resulting query region constraints.
 ///
 /// [c]: https://rust-lang.github.io/chalk/book/canonical_queries/canonicalization.html
-pub trait QueryTypeOp<'tcx>: fmt::Debug + Copy + TypeFoldable<'tcx> + 'tcx {
-    type QueryResponse: TypeFoldable<'tcx>;
+pub trait QueryTypeOp<'tcx>: fmt::Debug + Copy + TypeFoldable<TyCtxt<'tcx>> + 'tcx {
+    type QueryResponse: TypeFoldable<TyCtxt<'tcx>>;
 
     /// Give query the option for a simple fast path that never
     /// actually hits the tcx cache lookup etc. Return `Some(r)` with
diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/normalize.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/normalize.rs
index 8f0b4de31e6..5b216c07692 100644
--- a/compiler/rustc_trait_selection/src/traits/query/type_op/normalize.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/type_op/normalize.rs
@@ -1,7 +1,7 @@
 use crate::infer::canonical::{Canonical, CanonicalQueryResponse};
 use crate::traits::query::Fallible;
 use rustc_middle::ty::fold::TypeFoldable;
-use rustc_middle::ty::{self, Lift, ParamEnvAnd, Ty, TyCtxt};
+use rustc_middle::ty::{self, Lift, ParamEnvAnd, Ty, TyCtxt, TypeVisitableExt};
 use std::fmt;
 
 pub use rustc_middle::traits::query::type_op::Normalize;
@@ -24,7 +24,7 @@ where
     }
 }
 
-pub trait Normalizable<'tcx>: fmt::Debug + TypeFoldable<'tcx> + Lift<'tcx> + Copy {
+pub trait Normalizable<'tcx>: fmt::Debug + TypeFoldable<TyCtxt<'tcx>> + Lift<'tcx> + Copy {
     fn type_op_method(
         tcx: TyCtxt<'tcx>,
         canonicalized: Canonical<'tcx, ParamEnvAnd<'tcx, Normalize<Self>>>,
diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
index dae602908a3..4ad13dcb645 100644
--- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
@@ -9,7 +9,7 @@ use hir::LangItem;
 use rustc_hir as hir;
 use rustc_infer::traits::ObligationCause;
 use rustc_infer::traits::{Obligation, SelectionError, TraitObligation};
-use rustc_middle::ty::{self, Ty, TypeVisitable};
+use rustc_middle::ty::{self, Ty, TypeVisitableExt};
 use rustc_target::spec::abi::Abi;
 
 use crate::traits;
diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
index 5c5b2d6dac3..270f513ce3c 100644
--- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
@@ -12,7 +12,7 @@ use rustc_infer::infer::InferOk;
 use rustc_infer::infer::LateBoundRegionConversionTime::HigherRankedType;
 use rustc_middle::ty::{
     self, Binder, GenericParamDefKind, InternalSubsts, SubstsRef, ToPolyTraitRef, ToPredicate,
-    TraitRef, Ty, TyCtxt, TypeVisitable,
+    TraitRef, Ty, TyCtxt, TypeVisitableExt,
 };
 use rustc_session::config::TraitSolver;
 use rustc_span::def_id::DefId;
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 79c188d7f81..e7e0f8838a4 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -49,7 +49,7 @@ use rustc_middle::ty::fold::BottomUpFolder;
 use rustc_middle::ty::relate::TypeRelation;
 use rustc_middle::ty::SubstsRef;
 use rustc_middle::ty::{self, EarlyBinder, PolyProjectionPredicate, ToPolyTraitRef, ToPredicate};
-use rustc_middle::ty::{Ty, TyCtxt, TypeFoldable};
+use rustc_middle::ty::{Ty, TyCtxt, TypeFoldable, TypeVisitableExt};
 use rustc_session::config::TraitSolver;
 use rustc_span::symbol::sym;
 
@@ -1406,7 +1406,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
     /// The weird return type of this function allows it to be used with the `try` (`?`)
     /// operator within certain functions.
     #[inline(always)]
-    fn check_recursion_limit<T: Display + TypeFoldable<'tcx>, V>(
+    fn check_recursion_limit<T: Display + TypeFoldable<TyCtxt<'tcx>>, V>(
         &self,
         obligation: &Obligation<'tcx, T>,
         error_obligation: &Obligation<'tcx, V>,
diff --git a/compiler/rustc_trait_selection/src/traits/specialize/specialization_graph.rs b/compiler/rustc_trait_selection/src/traits/specialize/specialization_graph.rs
index 2e4a5cfe4bc..61ed9ef2ec1 100644
--- a/compiler/rustc_trait_selection/src/traits/specialize/specialization_graph.rs
+++ b/compiler/rustc_trait_selection/src/traits/specialize/specialization_graph.rs
@@ -4,7 +4,7 @@ use crate::traits;
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir::def_id::DefId;
 use rustc_middle::ty::fast_reject::{self, SimplifiedType, TreatParams};
-use rustc_middle::ty::{self, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, TyCtxt, TypeVisitableExt};
 
 pub use rustc_middle::traits::specialization_graph::*;
 
diff --git a/compiler/rustc_trait_selection/src/traits/structural_match.rs b/compiler/rustc_trait_selection/src/traits/structural_match.rs
index 32dd8f25b44..e38ae9381c1 100644
--- a/compiler/rustc_trait_selection/src/traits/structural_match.rs
+++ b/compiler/rustc_trait_selection/src/traits/structural_match.rs
@@ -1,8 +1,6 @@
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
-#[cfg(not(bootstrap))]
-use rustc_middle::ty::TypeVisitable;
-use rustc_middle::ty::{self, ir::TypeVisitor, Ty, TyCtxt, TypeSuperVisitable};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor};
 use rustc_span::Span;
 use std::ops::ControlFlow;
 
diff --git a/compiler/rustc_trait_selection/src/traits/util.rs b/compiler/rustc_trait_selection/src/traits/util.rs
index b5df583e3f4..0c55c35ffb4 100644
--- a/compiler/rustc_trait_selection/src/traits/util.rs
+++ b/compiler/rustc_trait_selection/src/traits/util.rs
@@ -4,7 +4,7 @@ use smallvec::SmallVec;
 
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir::def_id::DefId;
-use rustc_middle::ty::{self, ImplSubject, ToPredicate, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, ImplSubject, ToPredicate, Ty, TyCtxt, TypeVisitableExt};
 use rustc_middle::ty::{GenericArg, SubstsRef};
 
 use super::NormalizeExt;
diff --git a/compiler/rustc_trait_selection/src/traits/vtable.rs b/compiler/rustc_trait_selection/src/traits/vtable.rs
index 9f5c5bbeac8..a4e9928f8b2 100644
--- a/compiler/rustc_trait_selection/src/traits/vtable.rs
+++ b/compiler/rustc_trait_selection/src/traits/vtable.rs
@@ -4,7 +4,7 @@ use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
 use rustc_infer::traits::util::PredicateSet;
 use rustc_infer::traits::ImplSource;
-use rustc_middle::ty::visit::TypeVisitable;
+use rustc_middle::ty::visit::TypeVisitableExt;
 use rustc_middle::ty::InternalSubsts;
 use rustc_middle::ty::{self, GenericParamDefKind, ToPredicate, Ty, TyCtxt, VtblEntry};
 use rustc_span::{sym, Span};
diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs
index 6a881c233db..d498af359c5 100644
--- a/compiler/rustc_trait_selection/src/traits/wf.rs
+++ b/compiler/rustc_trait_selection/src/traits/wf.rs
@@ -3,7 +3,7 @@ use crate::traits;
 use rustc_hir as hir;
 use rustc_hir::lang_items::LangItem;
 use rustc_middle::ty::subst::{GenericArg, GenericArgKind, SubstsRef};
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
 use rustc_span::def_id::{DefId, LocalDefId, CRATE_DEF_ID};
 use rustc_span::{Span, DUMMY_SP};
 
diff --git a/compiler/rustc_traits/src/chalk/db.rs b/compiler/rustc_traits/src/chalk/db.rs
index e2b5d17e073..f8c8f744e6d 100644
--- a/compiler/rustc_traits/src/chalk/db.rs
+++ b/compiler/rustc_traits/src/chalk/db.rs
@@ -769,12 +769,12 @@ struct ReplaceOpaqueTyFolder<'tcx> {
     binder_index: ty::DebruijnIndex,
 }
 
-impl<'tcx> ty::ir::TypeFolder<TyCtxt<'tcx>> for ReplaceOpaqueTyFolder<'tcx> {
+impl<'tcx> ty::TypeFolder<TyCtxt<'tcx>> for ReplaceOpaqueTyFolder<'tcx> {
     fn interner(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
 
-    fn fold_binder<T: TypeFoldable<'tcx>>(
+    fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
         &mut self,
         t: ty::Binder<'tcx, T>,
     ) -> ty::Binder<'tcx, T> {
diff --git a/compiler/rustc_traits/src/chalk/lowering.rs b/compiler/rustc_traits/src/chalk/lowering.rs
index 7635f4bfec3..fe80de5a069 100644
--- a/compiler/rustc_traits/src/chalk/lowering.rs
+++ b/compiler/rustc_traits/src/chalk/lowering.rs
@@ -35,9 +35,8 @@ use rustc_ast::ast;
 use rustc_middle::traits::{ChalkEnvironmentAndGoal, ChalkRustInterner as RustInterner};
 use rustc_middle::ty::subst::{GenericArg, GenericArgKind, SubstsRef};
 use rustc_middle::ty::{
-    self,
-    ir::{TypeFolder, TypeVisitor},
-    Binder, Region, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable, TypeSuperVisitable, TypeVisitable,
+    self, Binder, Region, Ty, TyCtxt, TypeFoldable, TypeFolder, TypeSuperFoldable,
+    TypeSuperVisitable, TypeVisitable, TypeVisitor,
 };
 use rustc_span::def_id::DefId;
 
@@ -880,7 +879,7 @@ impl<'tcx> LowerInto<'tcx, chalk_solve::rust_ir::AliasEqBound<RustInterner<'tcx>
 /// It's important to note that because of prior substitution, we may have
 /// late-bound regions, even outside of fn contexts, since this is the best way
 /// to prep types for chalk lowering.
-pub(crate) fn collect_bound_vars<'tcx, T: TypeFoldable<'tcx>>(
+pub(crate) fn collect_bound_vars<'tcx, T: TypeFoldable<TyCtxt<'tcx>>>(
     interner: RustInterner<'tcx>,
     tcx: TyCtxt<'tcx>,
     ty: Binder<'tcx, T>,
@@ -931,7 +930,7 @@ impl<'tcx> BoundVarsCollector<'tcx> {
 }
 
 impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for BoundVarsCollector<'tcx> {
-    fn visit_binder<T: TypeVisitable<'tcx>>(
+    fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(
         &mut self,
         t: &Binder<'tcx, T>,
     ) -> ControlFlow<Self::BreakTy> {
@@ -1016,7 +1015,10 @@ impl<'a, 'tcx> TypeFolder<TyCtxt<'tcx>> for NamedBoundVarSubstitutor<'a, 'tcx> {
         self.tcx
     }
 
-    fn fold_binder<T: TypeFoldable<'tcx>>(&mut self, t: Binder<'tcx, T>) -> Binder<'tcx, T> {
+    fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
+        &mut self,
+        t: Binder<'tcx, T>,
+    ) -> Binder<'tcx, T> {
         self.binder_index.shift_in(1);
         let result = t.super_fold_with(self);
         self.binder_index.shift_out(1);
@@ -1072,7 +1074,10 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for ParamsSubstitutor<'tcx> {
         self.tcx
     }
 
-    fn fold_binder<T: TypeFoldable<'tcx>>(&mut self, t: Binder<'tcx, T>) -> Binder<'tcx, T> {
+    fn fold_binder<T: TypeFoldable<TyCtxt<'tcx>>>(
+        &mut self,
+        t: Binder<'tcx, T>,
+    ) -> Binder<'tcx, T> {
         self.binder_index.shift_in(1);
         let result = t.super_fold_with(self);
         self.binder_index.shift_out(1);
diff --git a/compiler/rustc_traits/src/chalk/mod.rs b/compiler/rustc_traits/src/chalk/mod.rs
index f33f9edd627..5855a8e28dd 100644
--- a/compiler/rustc_traits/src/chalk/mod.rs
+++ b/compiler/rustc_traits/src/chalk/mod.rs
@@ -9,7 +9,7 @@ pub(crate) mod lowering;
 use rustc_middle::infer::canonical::{CanonicalTyVarKind, CanonicalVarKind};
 use rustc_middle::traits::ChalkRustInterner;
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::{self, TyCtxt, TypeFoldable};
+use rustc_middle::ty::{self, TyCtxt, TypeFoldable, TypeVisitable};
 
 use rustc_infer::infer::canonical::{
     Canonical, CanonicalVarValues, Certainty, QueryRegionConstraints, QueryResponse,
diff --git a/compiler/rustc_traits/src/implied_outlives_bounds.rs b/compiler/rustc_traits/src/implied_outlives_bounds.rs
index abf0c1c5f3e..ddd4ca1436c 100644
--- a/compiler/rustc_traits/src/implied_outlives_bounds.rs
+++ b/compiler/rustc_traits/src/implied_outlives_bounds.rs
@@ -7,7 +7,7 @@ use rustc_infer::infer::outlives::components::{push_outlives_components, Compone
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::traits::query::OutlivesBound;
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
 use rustc_span::def_id::CRATE_DEF_ID;
 use rustc_span::source_map::DUMMY_SP;
 use rustc_trait_selection::infer::InferCtxtBuilderExt;
diff --git a/compiler/rustc_traits/src/normalize_erasing_regions.rs b/compiler/rustc_traits/src/normalize_erasing_regions.rs
index 2c18a034050..f0597f19225 100644
--- a/compiler/rustc_traits/src/normalize_erasing_regions.rs
+++ b/compiler/rustc_traits/src/normalize_erasing_regions.rs
@@ -1,7 +1,7 @@
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::traits::query::NoSolution;
 use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::{self, ParamEnvAnd, TyCtxt, TypeFoldable};
+use rustc_middle::ty::{self, ParamEnvAnd, TyCtxt, TypeFoldable, TypeVisitableExt};
 use rustc_trait_selection::traits::query::normalize::QueryNormalizeExt;
 use rustc_trait_selection::traits::{Normalized, ObligationCause};
 use std::sync::atomic::Ordering;
@@ -22,7 +22,7 @@ pub(crate) fn provide(p: &mut Providers) {
     };
 }
 
-fn try_normalize_after_erasing_regions<'tcx, T: TypeFoldable<'tcx> + PartialEq + Copy>(
+fn try_normalize_after_erasing_regions<'tcx, T: TypeFoldable<TyCtxt<'tcx>> + PartialEq + Copy>(
     tcx: TyCtxt<'tcx>,
     goal: ParamEnvAnd<'tcx, T>,
 ) -> Result<T, NoSolution> {
diff --git a/compiler/rustc_traits/src/type_op.rs b/compiler/rustc_traits/src/type_op.rs
index d34fce64dd7..e0fd487b3d3 100644
--- a/compiler/rustc_traits/src/type_op.rs
+++ b/compiler/rustc_traits/src/type_op.rs
@@ -161,7 +161,7 @@ fn type_op_normalize<'tcx, T>(
     key: ParamEnvAnd<'tcx, Normalize<T>>,
 ) -> Fallible<T>
 where
-    T: fmt::Debug + TypeFoldable<'tcx> + Lift<'tcx>,
+    T: fmt::Debug + TypeFoldable<TyCtxt<'tcx>> + Lift<'tcx>,
 {
     let (param_env, Normalize { value }) = key.into_parts();
     let Normalized { value, obligations } =
diff --git a/compiler/rustc_transmute/src/lib.rs b/compiler/rustc_transmute/src/lib.rs
index b3b9a67b26e..4b4a8ebd079 100644
--- a/compiler/rustc_transmute/src/lib.rs
+++ b/compiler/rustc_transmute/src/lib.rs
@@ -117,7 +117,7 @@ mod rustc {
             c: Const<'tcx>,
         ) -> Option<Self> {
             use rustc_middle::ty::ScalarInt;
-            use rustc_middle::ty::TypeVisitable;
+            use rustc_middle::ty::TypeVisitableExt;
             use rustc_span::symbol::sym;
 
             let c = c.eval(tcx, param_env);
diff --git a/compiler/rustc_ty_utils/src/consts.rs b/compiler/rustc_ty_utils/src/consts.rs
index 852156c24f4..ae824a31f75 100644
--- a/compiler/rustc_ty_utils/src/consts.rs
+++ b/compiler/rustc_ty_utils/src/consts.rs
@@ -5,7 +5,7 @@ use rustc_middle::mir::interpret::{LitToConstError, LitToConstInput};
 use rustc_middle::thir::visit;
 use rustc_middle::thir::visit::Visitor;
 use rustc_middle::ty::abstract_const::CastKind;
-use rustc_middle::ty::{self, Expr, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, Expr, TyCtxt, TypeVisitableExt};
 use rustc_middle::{mir, thir};
 use rustc_span::Span;
 use rustc_target::abi::VariantIdx;
diff --git a/compiler/rustc_ty_utils/src/instance.rs b/compiler/rustc_ty_utils/src/instance.rs
index de7230b0cfa..2eaeca73da7 100644
--- a/compiler/rustc_ty_utils/src/instance.rs
+++ b/compiler/rustc_ty_utils/src/instance.rs
@@ -3,7 +3,7 @@ use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::traits::CodegenObligationError;
 use rustc_middle::ty::subst::SubstsRef;
-use rustc_middle::ty::{self, Instance, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, Instance, TyCtxt, TypeVisitableExt};
 use rustc_span::sym;
 use rustc_trait_selection::traits;
 use traits::{translate_substs, Reveal};
diff --git a/compiler/rustc_ty_utils/src/layout.rs b/compiler/rustc_ty_utils/src/layout.rs
index 1a62794b0b4..a400fbfe683 100644
--- a/compiler/rustc_ty_utils/src/layout.rs
+++ b/compiler/rustc_ty_utils/src/layout.rs
@@ -7,7 +7,7 @@ use rustc_middle::ty::layout::{
     IntegerExt, LayoutCx, LayoutError, LayoutOf, TyAndLayout, MAX_SIMD_LANES,
 };
 use rustc_middle::ty::{
-    self, subst::SubstsRef, AdtDef, EarlyBinder, ReprOptions, Ty, TyCtxt, TypeVisitable,
+    self, subst::SubstsRef, AdtDef, EarlyBinder, ReprOptions, Ty, TyCtxt, TypeVisitableExt,
 };
 use rustc_session::{DataTypeKind, FieldInfo, FieldKind, SizeKind, VariantInfo};
 use rustc_span::symbol::Symbol;
diff --git a/compiler/rustc_ty_utils/src/ty.rs b/compiler/rustc_ty_utils/src/ty.rs
index f1af0073e4d..a47e7ce23e3 100644
--- a/compiler/rustc_ty_utils/src/ty.rs
+++ b/compiler/rustc_ty_utils/src/ty.rs
@@ -2,11 +2,9 @@ use rustc_data_structures::fx::{FxHashSet, FxIndexSet};
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_index::bit_set::BitSet;
-#[cfg(not(bootstrap))]
-use rustc_middle::ty::ir::TypeVisitable;
 use rustc_middle::ty::{
-    self, ir::TypeVisitor, Binder, EarlyBinder, Predicate, PredicateKind, ToPredicate, Ty, TyCtxt,
-    TypeSuperVisitable,
+    self, Binder, EarlyBinder, Predicate, PredicateKind, ToPredicate, Ty, TyCtxt,
+    TypeSuperVisitable, TypeVisitable, TypeVisitor,
 };
 use rustc_session::config::TraitSolver;
 use rustc_span::def_id::{DefId, CRATE_DEF_ID};
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 5541136ef49..58223f322b2 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -22,9 +22,9 @@ use rustc_hir::PredicateOrigin;
 use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_infer::infer::region_constraints::{Constraint, RegionConstraintData};
 use rustc_middle::middle::resolve_bound_vars as rbv;
-use rustc_middle::ty::fold::ir::TypeFolder;
+use rustc_middle::ty::fold::TypeFolder;
 use rustc_middle::ty::InternalSubsts;
-use rustc_middle::ty::TypeVisitable;
+use rustc_middle::ty::TypeVisitableExt;
 use rustc_middle::ty::{self, AdtKind, DefIdTree, EarlyBinder, Ty, TyCtxt};
 use rustc_middle::{bug, span_bug};
 use rustc_span::hygiene::{AstPass, MacroKind};
diff --git a/src/tools/clippy/clippy_lints/src/dereference.rs b/src/tools/clippy/clippy_lints/src/dereference.rs
index b4543aa2544..ef46e23123b 100644
--- a/src/tools/clippy/clippy_lints/src/dereference.rs
+++ b/src/tools/clippy/clippy_lints/src/dereference.rs
@@ -27,7 +27,7 @@ use rustc_middle::mir::{Rvalue, StatementKind};
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow, AutoBorrowMutability};
 use rustc_middle::ty::{
     self, Binder, BoundVariableKind, Clause, EarlyBinder, FnSig, GenericArgKind, List, ParamTy, PredicateKind,
-    ProjectionPredicate, Ty, TyCtxt, TypeVisitable, TypeckResults,
+    ProjectionPredicate, Ty, TyCtxt, TypeVisitableExt, TypeckResults,
 };
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::{symbol::sym, Span, Symbol};
diff --git a/src/tools/clippy/clippy_lints/src/eta_reduction.rs b/src/tools/clippy/clippy_lints/src/eta_reduction.rs
index ddade65c515..b2071f4dcb1 100644
--- a/src/tools/clippy/clippy_lints/src/eta_reduction.rs
+++ b/src/tools/clippy/clippy_lints/src/eta_reduction.rs
@@ -11,7 +11,7 @@ use rustc_hir::{Closure, Expr, ExprKind, Param, PatKind, Unsafety};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow};
 use rustc_middle::ty::binding::BindingMode;
-use rustc_middle::ty::{self, EarlyBinder, SubstsRef, Ty, TypeVisitable};
+use rustc_middle::ty::{self, EarlyBinder, SubstsRef, Ty, TypeVisitableExt};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::symbol::sym;
 
diff --git a/src/tools/clippy/clippy_lints/src/mut_key.rs b/src/tools/clippy/clippy_lints/src/mut_key.rs
index 3cc765108d7..5a533261cad 100644
--- a/src/tools/clippy/clippy_lints/src/mut_key.rs
+++ b/src/tools/clippy/clippy_lints/src/mut_key.rs
@@ -3,7 +3,7 @@ use clippy_utils::{def_path_def_ids, trait_ref_of_method};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::ty::TypeVisitable;
+use rustc_middle::ty::TypeVisitableExt;
 use rustc_middle::ty::{Adt, Array, Ref, Slice, Tuple, Ty};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::def_id::LocalDefId;
diff --git a/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs b/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
index 996ea6ed723..da3b6fa9899 100644
--- a/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
+++ b/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
@@ -18,7 +18,7 @@ use rustc_hir_typeck::expr_use_visitor as euv;
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::mir::FakeReadCause;
-use rustc_middle::ty::{self, TypeVisitable};
+use rustc_middle::ty::{self, TypeVisitableExt};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::symbol::kw;
diff --git a/src/tools/clippy/clippy_lints/src/transmute/transmute_ptr_to_ref.rs b/src/tools/clippy/clippy_lints/src/transmute/transmute_ptr_to_ref.rs
index 54ac04df1c1..6bdb9aa5a26 100644
--- a/src/tools/clippy/clippy_lints/src/transmute/transmute_ptr_to_ref.rs
+++ b/src/tools/clippy/clippy_lints/src/transmute/transmute_ptr_to_ref.rs
@@ -6,7 +6,7 @@ use clippy_utils::sugg;
 use rustc_errors::Applicability;
 use rustc_hir::{self as hir, Expr, GenericArg, Mutability, Path, TyKind};
 use rustc_lint::LateContext;
-use rustc_middle::ty::{self, Ty, TypeVisitable};
+use rustc_middle::ty::{self, Ty, TypeVisitableExt};
 
 /// Checks for `transmute_ptr_to_ref` lint.
 /// Returns `true` if it's triggered, otherwise returns `false`.
diff --git a/src/tools/clippy/clippy_lints/src/transmute/useless_transmute.rs b/src/tools/clippy/clippy_lints/src/transmute/useless_transmute.rs
index 871c3fadbba..56207fe767c 100644
--- a/src/tools/clippy/clippy_lints/src/transmute/useless_transmute.rs
+++ b/src/tools/clippy/clippy_lints/src/transmute/useless_transmute.rs
@@ -4,7 +4,7 @@ use clippy_utils::sugg;
 use rustc_errors::Applicability;
 use rustc_hir::Expr;
 use rustc_lint::LateContext;
-use rustc_middle::ty::{self, Ty, TypeVisitable};
+use rustc_middle::ty::{self, Ty, TypeVisitableExt};
 
 /// Checks for `useless_transmute` lint.
 /// Returns `true` if it's triggered, otherwise returns `false`.
diff --git a/src/tools/clippy/clippy_lints/src/types/redundant_allocation.rs b/src/tools/clippy/clippy_lints/src/types/redundant_allocation.rs
index f9b9a66b5fa..f7adc9d3555 100644
--- a/src/tools/clippy/clippy_lints/src/types/redundant_allocation.rs
+++ b/src/tools/clippy/clippy_lints/src/types/redundant_allocation.rs
@@ -5,7 +5,7 @@ use rustc_errors::Applicability;
 use rustc_hir::{self as hir, def_id::DefId, QPath, TyKind};
 use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_lint::LateContext;
-use rustc_middle::ty::TypeVisitable;
+use rustc_middle::ty::TypeVisitableExt;
 use rustc_span::symbol::sym;
 
 use super::{utils, REDUNDANT_ALLOCATION};
diff --git a/src/tools/clippy/clippy_lints/src/types/vec_box.rs b/src/tools/clippy/clippy_lints/src/types/vec_box.rs
index 7a3c7cd8a99..d3062f3d2e3 100644
--- a/src/tools/clippy/clippy_lints/src/types/vec_box.rs
+++ b/src/tools/clippy/clippy_lints/src/types/vec_box.rs
@@ -7,7 +7,7 @@ use rustc_hir::{self as hir, def_id::DefId, GenericArg, QPath, TyKind};
 use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_lint::LateContext;
 use rustc_middle::ty::layout::LayoutOf;
-use rustc_middle::ty::TypeVisitable;
+use rustc_middle::ty::TypeVisitableExt;
 use rustc_span::symbol::sym;
 
 use super::VEC_BOX;
diff --git a/src/tools/clippy/clippy_lints/src/zero_sized_map_values.rs b/src/tools/clippy/clippy_lints/src/zero_sized_map_values.rs
index 6cf2a955fd5..93e4b023c5c 100644
--- a/src/tools/clippy/clippy_lints/src/zero_sized_map_values.rs
+++ b/src/tools/clippy/clippy_lints/src/zero_sized_map_values.rs
@@ -5,7 +5,7 @@ use rustc_hir::{self as hir, HirId, ItemKind, Node};
 use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::layout::LayoutOf as _;
-use rustc_middle::ty::{Adt, Ty, TypeVisitable};
+use rustc_middle::ty::{Adt, Ty, TypeVisitableExt};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::sym;
 
diff --git a/src/tools/clippy/clippy_utils/src/lib.rs b/src/tools/clippy/clippy_utils/src/lib.rs
index b2edd1bbfef..f02f8ecb43d 100644
--- a/src/tools/clippy/clippy_utils/src/lib.rs
+++ b/src/tools/clippy/clippy_utils/src/lib.rs
@@ -104,7 +104,7 @@ use rustc_middle::ty::fast_reject::SimplifiedType::{
     PtrSimplifiedType, SliceSimplifiedType, StrSimplifiedType, UintSimplifiedType,
 };
 use rustc_middle::ty::{
-    layout::IntegerExt, BorrowKind, ClosureKind, DefIdTree, Ty, TyCtxt, TypeAndMut, TypeVisitable, UpvarCapture,
+    layout::IntegerExt, BorrowKind, ClosureKind, DefIdTree, Ty, TyCtxt, TypeAndMut, TypeVisitableExt, UpvarCapture,
 };
 use rustc_middle::ty::{FloatTy, IntTy, UintTy};
 use rustc_span::hygiene::{ExpnKind, MacroKind};
diff --git a/src/tools/clippy/clippy_utils/src/mir/possible_borrower.rs b/src/tools/clippy/clippy_utils/src/mir/possible_borrower.rs
index e9dc7351b58..920ce8e655b 100644
--- a/src/tools/clippy/clippy_utils/src/mir/possible_borrower.rs
+++ b/src/tools/clippy/clippy_utils/src/mir/possible_borrower.rs
@@ -4,7 +4,7 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_index::bit_set::{BitSet, HybridBitSet};
 use rustc_lint::LateContext;
 use rustc_middle::mir::{self, visit::Visitor as _, Mutability};
-use rustc_middle::ty::{self, visit::ir::TypeVisitor, TyCtxt};
+use rustc_middle::ty::{self, visit::TypeVisitor, TyCtxt};
 use rustc_mir_dataflow::{impls::MaybeStorageLive, Analysis, ResultsCursor};
 use std::borrow::Cow;
 use std::ops::ControlFlow;
diff --git a/src/tools/clippy/clippy_utils/src/ty.rs b/src/tools/clippy/clippy_utils/src/ty.rs
index 2ed301fcc22..34b9bb5994e 100644
--- a/src/tools/clippy/clippy_utils/src/ty.rs
+++ b/src/tools/clippy/clippy_utils/src/ty.rs
@@ -17,8 +17,8 @@ use rustc_lint::LateContext;
 use rustc_middle::mir::interpret::{ConstValue, Scalar};
 use rustc_middle::ty::{
     self, AdtDef, AliasTy, AssocKind, Binder, BoundRegion, DefIdTree, FnSig, IntTy, List, ParamEnv, Predicate,
-    PredicateKind, Region, RegionKind, SubstsRef, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, ir::TypeVisitor, UintTy,
-    VariantDef, VariantDiscr,
+    PredicateKind, Region, RegionKind, SubstsRef, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor, UintTy,
+    VariantDef, VariantDiscr, TypeVisitableExt,
 };
 use rustc_middle::ty::{GenericArg, GenericArgKind};
 use rustc_span::symbol::Ident;
@@ -847,7 +847,7 @@ pub fn for_each_top_level_late_bound_region<B>(
                 ControlFlow::Continue(())
             }
         }
-        fn visit_binder<T: TypeVisitable<'tcx>>(&mut self, t: &Binder<'tcx, T>) -> ControlFlow<Self::BreakTy> {
+        fn visit_binder<T: TypeVisitable<TyCtxt<'tcx>>>(&mut self, t: &Binder<'tcx, T>) -> ControlFlow<Self::BreakTy> {
             self.index += 1;
             let res = t.super_visit_with(self);
             self.index -= 1;
diff --git a/tests/ui/impl-trait/normalize-tait-in-const.rs b/tests/ui/impl-trait/normalize-tait-in-const.rs
index 020bcbb8396..d2e34c00b64 100644
--- a/tests/ui/impl-trait/normalize-tait-in-const.rs
+++ b/tests/ui/impl-trait/normalize-tait-in-const.rs
@@ -2,6 +2,7 @@
 // failure-status: 101
 // normalize-stderr-test "note: .*\n\n" -> ""
 // normalize-stderr-test "thread 'rustc' panicked.*\n" -> ""
+// normalize-stderr-test "(error: internal compiler error: [^:]+):\d+:\d+: " -> "$1:LL:CC: "
 // rustc-env:RUST_BACKTRACE=0
 
 #![feature(type_alias_impl_trait)]
diff --git a/tests/ui/impl-trait/normalize-tait-in-const.stderr b/tests/ui/impl-trait/normalize-tait-in-const.stderr
index 99eed29207b..84b00918724 100644
--- a/tests/ui/impl-trait/normalize-tait-in-const.stderr
+++ b/tests/ui/impl-trait/normalize-tait-in-const.stderr
@@ -1,4 +1,4 @@
-error: internal compiler error: compiler/rustc_middle/src/ty/normalize_erasing_regions.rs:201:90: Failed to normalize <for<'a, 'b> fn(&'a Alias<'b>) {foo} as std::ops::FnOnce<(&&S,)>>::Output, maybe try to call `try_normalize_erasing_regions` instead
+error: internal compiler error: compiler/rustc_middle/src/ty/normalize_erasing_regions.rs:LL:CC: Failed to normalize <for<'a, 'b> fn(&'a Alias<'b>) {foo} as std::ops::FnOnce<(&&S,)>>::Output, maybe try to call `try_normalize_erasing_regions` instead
 
 query stack during panic:
 #0 [eval_to_allocation_raw] const-evaluating + checking `BAR`