Auto merge of #110401 - fee1-dead-contrib:rollup-1f2smz2, r=fee1-dead

Rollup of 3 pull requests

Successful merges:

 - #109665 (Remove `remap_env_constness` in queries)
 - #110345 (Remove `TypeSuper{Foldable,Visitable}` impls for `Region`.)
 - #110396 (Use lint via `lint_defs` instead of `lints`)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

22 files changed, 79 insertions, 137 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 12be36ef861..094eb6fa67e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4775,7 +4775,7 @@ dependencies = [
  "rustc_hir",
  "rustc_index",
  "rustc_infer",
- "rustc_lint",
+ "rustc_lint_defs",
  "rustc_macros",
  "rustc_middle",
  "rustc_session",
diff --git a/compiler/rustc_hir_analysis/Cargo.toml b/compiler/rustc_hir_analysis/Cargo.toml
index fab16b80fb5..a64466884d8 100644
--- a/compiler/rustc_hir_analysis/Cargo.toml
+++ b/compiler/rustc_hir_analysis/Cargo.toml
@@ -23,7 +23,7 @@ rustc_span = { path = "../rustc_span" }
 rustc_index = { path = "../rustc_index" }
 rustc_infer = { path = "../rustc_infer" }
 rustc_trait_selection = { path = "../rustc_trait_selection" }
-rustc_lint = { path = "../rustc_lint" }
+rustc_lint_defs = { path = "../rustc_lint_defs" }
 rustc_type_ir = { path = "../rustc_type_ir" }
 rustc_feature = { path = "../rustc_feature" }
 thin-vec = "0.2.12"
diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs
index 0bb98fdf2a2..0c54fd70c9b 100644
--- a/compiler/rustc_hir_analysis/src/check/check.rs
+++ b/compiler/rustc_hir_analysis/src/check/check.rs
@@ -15,7 +15,7 @@ use rustc_infer::infer::opaque_types::ConstrainOpaqueTypeRegionVisitor;
 use rustc_infer::infer::outlives::env::OutlivesEnvironment;
 use rustc_infer::infer::{DefiningAnchor, RegionVariableOrigin, TyCtxtInferExt};
 use rustc_infer::traits::{Obligation, TraitEngineExt as _};
-use rustc_lint::builtin::REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS;
+use rustc_lint_defs::builtin::REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::stability::EvalResult;
 use rustc_middle::ty::layout::{LayoutError, MAX_SIMD_LANES};
diff --git a/compiler/rustc_hir_analysis/src/variance/mod.rs b/compiler/rustc_hir_analysis/src/variance/mod.rs
index 0a45119ff05..4d240e90b14 100644
--- a/compiler/rustc_hir_analysis/src/variance/mod.rs
+++ b/compiler/rustc_hir_analysis/src/variance/mod.rs
@@ -105,7 +105,7 @@ fn variance_of_opaque(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Varianc
             if let ty::RegionKind::ReEarlyBound(ebr) = r.kind() {
                 self.variances[ebr.index as usize] = ty::Invariant;
             }
-            r.super_visit_with(self)
+            ControlFlow::Continue(())
         }
 
         #[instrument(level = "trace", skip(self), ret)]
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 2875448ee15..ce70bcc5c85 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
@@ -13,7 +13,7 @@ use rustc_hir::intravisit::Visitor;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::error::ExpectedFound;
 use rustc_middle::ty::print::RegionHighlightMode;
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeSuperVisitable, TypeVisitor};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitor};
 use rustc_span::Span;
 
 use std::ops::ControlFlow;
@@ -81,7 +81,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
                     self.highlight.highlighting_region(r, self.counter);
                     self.counter += 1;
                 }
-                r.super_visit_with(self)
+                ControlFlow::Continue(())
             }
         }
 
diff --git a/compiler/rustc_macros/src/query.rs b/compiler/rustc_macros/src/query.rs
index f85ba38003c..a8b25ff66d7 100644
--- a/compiler/rustc_macros/src/query.rs
+++ b/compiler/rustc_macros/src/query.rs
@@ -112,9 +112,6 @@ struct QueryModifiers {
     /// Use a separate query provider for local and extern crates
     separate_provide_extern: Option<Ident>,
 
-    /// Always remap the ParamEnv's constness before hashing.
-    remap_env_constness: Option<Ident>,
-
     /// Generate a `feed` method to set the query's value from another query.
     feedable: Option<Ident>,
 }
@@ -130,7 +127,6 @@ fn parse_query_modifiers(input: ParseStream<'_>) -> Result<QueryModifiers> {
     let mut eval_always = None;
     let mut depth_limit = None;
     let mut separate_provide_extern = None;
-    let mut remap_env_constness = None;
     let mut feedable = None;
 
     while !input.is_empty() {
@@ -189,8 +185,6 @@ fn parse_query_modifiers(input: ParseStream<'_>) -> Result<QueryModifiers> {
             try_insert!(depth_limit = modifier);
         } else if modifier == "separate_provide_extern" {
             try_insert!(separate_provide_extern = modifier);
-        } else if modifier == "remap_env_constness" {
-            try_insert!(remap_env_constness = modifier);
         } else if modifier == "feedable" {
             try_insert!(feedable = modifier);
         } else {
@@ -211,7 +205,6 @@ fn parse_query_modifiers(input: ParseStream<'_>) -> Result<QueryModifiers> {
         eval_always,
         depth_limit,
         separate_provide_extern,
-        remap_env_constness,
         feedable,
     })
 }
@@ -332,7 +325,6 @@ pub fn rustc_queries(input: TokenStream) -> TokenStream {
             eval_always,
             depth_limit,
             separate_provide_extern,
-            remap_env_constness,
         );
 
         if modifiers.cache.is_some() {
diff --git a/compiler/rustc_middle/src/infer/canonical.rs b/compiler/rustc_middle/src/infer/canonical.rs
index b5b712c367d..e63121475a1 100644
--- a/compiler/rustc_middle/src/infer/canonical.rs
+++ b/compiler/rustc_middle/src/infer/canonical.rs
@@ -348,14 +348,6 @@ impl<'tcx, R> Canonical<'tcx, QueryResponse<'tcx, R>> {
     }
 }
 
-impl<'tcx, R> Canonical<'tcx, ty::ParamEnvAnd<'tcx, R>> {
-    #[inline]
-    pub fn without_const(mut self) -> Self {
-        self.value = self.value.without_const();
-        self
-    }
-}
-
 impl<'tcx, V> Canonical<'tcx, V> {
     /// Allows you to map the `value` of a canonical while keeping the
     /// same set of bound variables.
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 7a5a1603585..6fc9190b090 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -1094,7 +1094,6 @@ rustc_queries! {
         key: ty::ParamEnvAnd<'tcx, mir::ConstantKind<'tcx>>
     ) -> Option<mir::DestructuredConstant<'tcx>> {
         desc { "destructuring MIR constant"}
-        remap_env_constness
     }
 
     /// Dereference a constant reference or raw pointer and turn the result into a constant
@@ -1103,7 +1102,6 @@ rustc_queries! {
         key: ty::ParamEnvAnd<'tcx, mir::ConstantKind<'tcx>>
     ) -> mir::ConstantKind<'tcx> {
         desc { "dereferencing MIR constant" }
-        remap_env_constness
     }
 
     query const_caller_location(key: (rustc_span::Symbol, u32, u32)) -> ConstValue<'tcx> {
@@ -1346,32 +1344,26 @@ rustc_queries! {
     /// `ty.is_copy()`, etc, since that will prune the environment where possible.
     query is_copy_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` is `Copy`", env.value }
-        remap_env_constness
     }
     /// Query backing `Ty::is_sized`.
     query is_sized_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` is `Sized`", env.value }
-        remap_env_constness
     }
     /// Query backing `Ty::is_freeze`.
     query is_freeze_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` is freeze", env.value }
-        remap_env_constness
     }
     /// Query backing `Ty::is_unpin`.
     query is_unpin_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` is `Unpin`", env.value }
-        remap_env_constness
     }
     /// Query backing `Ty::needs_drop`.
     query needs_drop_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` needs drop", env.value }
-        remap_env_constness
     }
     /// Query backing `Ty::has_significant_drop_raw`.
     query has_significant_drop_raw(env: ty::ParamEnvAnd<'tcx, Ty<'tcx>>) -> bool {
         desc { "computing whether `{}` has a significant drop", env.value }
-        remap_env_constness
     }
 
     /// Query backing `Ty::is_structural_eq_shallow`.
@@ -1411,7 +1403,6 @@ rustc_queries! {
     ) -> Result<ty::layout::TyAndLayout<'tcx>, ty::layout::LayoutError<'tcx>> {
         depth_limit
         desc { "computing layout of `{}`", key.value }
-        remap_env_constness
     }
 
     /// Compute a `FnAbi` suitable for indirect calls, i.e. to `fn` pointers.
@@ -1422,7 +1413,6 @@ rustc_queries! {
         key: ty::ParamEnvAnd<'tcx, (ty::PolyFnSig<'tcx>, &'tcx ty::List<Ty<'tcx>>)>
     ) -> Result<&'tcx abi::call::FnAbi<'tcx, Ty<'tcx>>, ty::layout::FnAbiError<'tcx>> {
         desc { "computing call ABI of `{}` function pointers", key.value.0 }
-        remap_env_constness
     }
 
     /// Compute a `FnAbi` suitable for declaring/defining an `fn` instance, and for
@@ -1434,7 +1424,6 @@ rustc_queries! {
         key: ty::ParamEnvAnd<'tcx, (ty::Instance<'tcx>, &'tcx ty::List<Ty<'tcx>>)>
     ) -> Result<&'tcx abi::call::FnAbi<'tcx, Ty<'tcx>>, ty::layout::FnAbiError<'tcx>> {
         desc { "computing call ABI of `{}`", key.value.0 }
-        remap_env_constness
     }
 
     query dylib_dependency_formats(_: CrateNum)
@@ -1937,7 +1926,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "normalizing `{}`", goal.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: invoke `try_normalize_erasing_regions` instead.
@@ -1945,7 +1933,6 @@ rustc_queries! {
         goal: ParamEnvAnd<'tcx, GenericArg<'tcx>>
     ) -> Result<GenericArg<'tcx>, NoSolution> {
         desc { "normalizing `{}`", goal.value }
-        remap_env_constness
     }
 
     query implied_outlives_bounds(
@@ -1955,7 +1942,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "computing implied outlives bounds for `{}`", goal.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly:
@@ -1967,7 +1953,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "computing dropck types for `{}`", goal.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: invoke `infcx.predicate_may_hold()` or
@@ -1995,7 +1980,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "evaluating `type_op_ascribe_user_type` `{:?}`", goal.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: part of the `Eq` type-op
@@ -2006,7 +1990,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "evaluating `type_op_eq` `{:?}`", goal.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: part of the `Subtype` type-op
@@ -2017,7 +2000,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "evaluating `type_op_subtype` `{:?}`", goal.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: part of the `ProvePredicate` type-op
@@ -2038,7 +2020,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "normalizing `{}`", goal.value.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: part of the `Normalize` type-op
@@ -2049,7 +2030,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "normalizing `{:?}`", goal.value.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: part of the `Normalize` type-op
@@ -2060,7 +2040,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "normalizing `{:?}`", goal.value.value.value }
-        remap_env_constness
     }
 
     /// Do not call this query directly: part of the `Normalize` type-op
@@ -2071,7 +2050,6 @@ rustc_queries! {
         NoSolution,
     > {
         desc { "normalizing `{:?}`", goal.value.value.value }
-        remap_env_constness
     }
 
     query subst_and_check_impossible_predicates(key: (DefId, SubstsRef<'tcx>)) -> bool {
@@ -2093,7 +2071,6 @@ rustc_queries! {
         goal: CanonicalTyGoal<'tcx>
     ) -> MethodAutoderefStepsResult<'tcx> {
         desc { "computing autoderef types for `{}`", goal.value.value }
-        remap_env_constness
     }
 
     query supported_target_features(_: CrateNum) -> &'tcx FxHashMap<String, Option<Symbol>> {
@@ -2138,7 +2115,6 @@ rustc_queries! {
         key: ty::ParamEnvAnd<'tcx, (DefId, SubstsRef<'tcx>)>
     ) -> Result<Option<ty::Instance<'tcx>>, ErrorGuaranteed> {
         desc { "resolving instance `{}`", ty::Instance::new(key.value.0, key.value.1) }
-        remap_env_constness
     }
 
     query resolve_instance_of_const_arg(
@@ -2148,7 +2124,6 @@ rustc_queries! {
             "resolving instance of the const argument `{}`",
             ty::Instance::new(key.value.0.to_def_id(), key.value.2),
         }
-        remap_env_constness
     }
 
     query reveal_opaque_types_in_bounds(key: &'tcx ty::List<ty::Predicate<'tcx>>) -> &'tcx ty::List<ty::Predicate<'tcx>> {
diff --git a/compiler/rustc_middle/src/ty/fold.rs b/compiler/rustc_middle/src/ty/fold.rs
index 203e16bea27..25890eb15cd 100644
--- a/compiler/rustc_middle/src/ty/fold.rs
+++ b/compiler/rustc_middle/src/ty/fold.rs
@@ -37,7 +37,8 @@ where
     }
 
     fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
-        let r = r.super_fold_with(self);
+        // This one is a little different, because `super_fold_with` is not
+        // implemented on non-recursive `Region`.
         (self.lt_op)(r)
     }
 
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index 2e516f291bc..bc202b027bd 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -1850,12 +1850,6 @@ impl<'tcx, T> ParamEnvAnd<'tcx, T> {
     pub fn into_parts(self) -> (ParamEnv<'tcx>, T) {
         (self.param_env, self.value)
     }
-
-    #[inline]
-    pub fn without_const(mut self) -> Self {
-        self.param_env = self.param_env.without_const();
-        self
-    }
 }
 
 #[derive(Copy, Clone, Debug, HashStable, Encodable, Decodable)]
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
index 72caadaf661..af76cf7cc4e 100644
--- a/compiler/rustc_middle/src/ty/print/pretty.rs
+++ b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -2518,7 +2518,7 @@ impl<'tcx> FmtPrinter<'_, 'tcx> {
                     self.used_region_names.insert(name);
                 }
 
-                r.super_visit_with(self)
+                ControlFlow::Continue(())
             }
 
             // We collect types in order to prevent really large types from compiling for
diff --git a/compiler/rustc_middle/src/ty/query.rs b/compiler/rustc_middle/src/ty/query.rs
index fa9fea72344..97592cbc567 100644
--- a/compiler/rustc_middle/src/ty/query.rs
+++ b/compiler/rustc_middle/src/ty/query.rs
@@ -202,16 +202,6 @@ macro_rules! separate_provide_extern_default {
     };
 }
 
-macro_rules! opt_remap_env_constness {
-    ([][$name:ident]) => {};
-    ([(remap_env_constness) $($rest:tt)*][$name:ident]) => {
-        let $name = $name.without_const();
-    };
-    ([$other:tt $($modifiers:tt)*][$name:ident]) => {
-        opt_remap_env_constness!([$($modifiers)*][$name])
-    };
-}
-
 macro_rules! define_callbacks {
     (
      $($(#[$attr:meta])*
@@ -353,7 +343,6 @@ macro_rules! define_callbacks {
             #[inline(always)]
             pub fn $name(self, key: query_helper_param_ty!($($K)*)) {
                 let key = key.into_query_param();
-                opt_remap_env_constness!([$($modifiers)*][key]);
 
                 match try_get_cached(self.tcx, &self.tcx.query_system.caches.$name, &key) {
                     Some(_) => return,
@@ -372,7 +361,6 @@ macro_rules! define_callbacks {
             #[inline(always)]
             pub fn $name(self, key: query_helper_param_ty!($($K)*)) {
                 let key = key.into_query_param();
-                opt_remap_env_constness!([$($modifiers)*][key]);
 
                 match try_get_cached(self.tcx, &self.tcx.query_system.caches.$name, &key) {
                     Some(_) => return,
@@ -402,7 +390,6 @@ macro_rules! define_callbacks {
             pub fn $name(self, key: query_helper_param_ty!($($K)*)) -> $V
             {
                 let key = key.into_query_param();
-                opt_remap_env_constness!([$($modifiers)*][key]);
 
                 restore::<$V>(match try_get_cached(self.tcx, &self.tcx.query_system.caches.$name, &key) {
                     Some(value) => value,
@@ -492,7 +479,6 @@ macro_rules! define_feedable {
             #[inline(always)]
             pub fn $name(self, value: query_provided::$name<'tcx>) -> $V {
                 let key = self.key().into_query_param();
-                opt_remap_env_constness!([$($modifiers)*][key]);
 
                 let tcx = self.tcx;
                 let erased = query_provided_to_value::$name(tcx, value);
diff --git a/compiler/rustc_middle/src/ty/structural_impls.rs b/compiler/rustc_middle/src/ty/structural_impls.rs
index 5c604bb6db2..619fcea8b7d 100644
--- a/compiler/rustc_middle/src/ty/structural_impls.rs
+++ b/compiler/rustc_middle/src/ty/structural_impls.rs
@@ -583,24 +583,6 @@ impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for ty::Region<'tcx> {
     }
 }
 
-impl<'tcx> TypeSuperFoldable<TyCtxt<'tcx>> for ty::Region<'tcx> {
-    fn try_super_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
-        self,
-        _folder: &mut F,
-    ) -> Result<Self, F::Error> {
-        Ok(self)
-    }
-}
-
-impl<'tcx> TypeSuperVisitable<TyCtxt<'tcx>> for ty::Region<'tcx> {
-    fn super_visit_with<V: TypeVisitor<TyCtxt<'tcx>>>(
-        &self,
-        _visitor: &mut V,
-    ) -> ControlFlow<V::BreakTy> {
-        ControlFlow::Continue(())
-    }
-}
-
 impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for ty::Predicate<'tcx> {
     fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
         self,
diff --git a/compiler/rustc_middle/src/ty/visit.rs b/compiler/rustc_middle/src/ty/visit.rs
index 08a62c900f9..24a1f04c7e3 100644
--- a/compiler/rustc_middle/src/ty/visit.rs
+++ b/compiler/rustc_middle/src/ty/visit.rs
@@ -364,7 +364,7 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for ValidateBoundVars<'tcx> {
             _ => (),
         };
 
-        r.super_visit_with(self)
+        ControlFlow::Continue(())
     }
 }
 
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index 8a203dec86b..ed82b9c0152 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -450,7 +450,7 @@ fn is_impossible_method(tcx: TyCtxt<'_>, (impl_def_id, trait_item_def_id): (DefI
             {
                 return ControlFlow::Break(());
             }
-            r.super_visit_with(self)
+            ControlFlow::Continue(())
         }
         fn visit_const(&mut self, ct: ty::Const<'tcx>) -> ControlFlow<Self::BreakTy> {
             if let ty::ConstKind::Param(param) = ct.kind()
diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/prove_predicate.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/prove_predicate.rs
index b63da28e274..baa2fbb6751 100644
--- a/compiler/rustc_trait_selection/src/traits/query/type_op/prove_predicate.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/type_op/prove_predicate.rs
@@ -32,14 +32,8 @@ impl<'tcx> super::QueryTypeOp<'tcx> for ProvePredicate<'tcx> {
 
     fn perform_query(
         tcx: TyCtxt<'tcx>,
-        mut canonicalized: Canonical<'tcx, ParamEnvAnd<'tcx, Self>>,
+        canonicalized: Canonical<'tcx, ParamEnvAnd<'tcx, Self>>,
     ) -> Fallible<CanonicalQueryResponse<'tcx, ()>> {
-        match canonicalized.value.value.predicate.kind().skip_binder() {
-            ty::PredicateKind::Clause(ty::Clause::Trait(pred)) => {
-                canonicalized.value.param_env.remap_constness_with(pred.constness);
-            }
-            _ => canonicalized.value.param_env = canonicalized.value.param_env.without_const(),
-        }
         tcx.type_op_prove_predicate(canonicalized)
     }
 }
diff --git a/compiler/rustc_traits/src/chalk/lowering.rs b/compiler/rustc_traits/src/chalk/lowering.rs
index 2be72879b7b..31eea22d72b 100644
--- a/compiler/rustc_traits/src/chalk/lowering.rs
+++ b/compiler/rustc_traits/src/chalk/lowering.rs
@@ -998,7 +998,7 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for BoundVarsCollector<'tcx> {
             _ => (),
         };
 
-        r.super_visit_with(self)
+        ControlFlow::Continue(())
     }
 }
 
@@ -1048,7 +1048,7 @@ impl<'a, 'tcx> TypeFolder<TyCtxt<'tcx>> for NamedBoundVarSubstitutor<'a, 'tcx> {
             _ => (),
         };
 
-        r.super_fold_with(self)
+        r
     }
 }
 
@@ -1142,7 +1142,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for ParamsSubstitutor<'tcx> {
                 }
             },
 
-            _ => r.super_fold_with(self),
+            _ => r,
         }
     }
 }
@@ -1223,6 +1223,6 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for PlaceholdersCollector {
             _ => (),
         };
 
-        r.super_visit_with(self)
+        ControlFlow::Continue(())
     }
 }
diff --git a/compiler/rustc_traits/src/type_op.rs b/compiler/rustc_traits/src/type_op.rs
index e0fd487b3d3..19622112f2a 100644
--- a/compiler/rustc_traits/src/type_op.rs
+++ b/compiler/rustc_traits/src/type_op.rs
@@ -89,6 +89,7 @@ fn relate_mir_and_user_substs<'tcx>(
     def_id: hir::def_id::DefId,
     user_substs: UserSubsts<'tcx>,
 ) -> Result<(), NoSolution> {
+    let param_env = param_env.without_const();
     let UserSubsts { user_self_ty, substs } = user_substs;
     let tcx = ocx.infcx.tcx;
     let cause = ObligationCause::dummy_with_span(span);
diff --git a/compiler/rustc_type_ir/src/fold.rs b/compiler/rustc_type_ir/src/fold.rs
index 3a053d4c6a9..371c6119122 100644
--- a/compiler/rustc_type_ir/src/fold.rs
+++ b/compiler/rustc_type_ir/src/fold.rs
@@ -16,8 +16,10 @@
 //!   - Types of interest, for which the methods delegate to the folder.
 //!   - All other types, including generic containers like `Vec` and `Option`.
 //!     It defines a "skeleton" of how they should be folded.
-//! - `TypeSuperFoldable`. This is implemented only for each type of interest,
-//!   and defines the folding "skeleton" for these types.
+//! - `TypeSuperFoldable`. This is implemented only for recursive types of
+//!   interest, and defines the folding "skeleton" for these types. (This
+//!   excludes `Region` because it is non-recursive, i.e. it never contains
+//!   other types of interest.)
 //! - `TypeFolder`/`FallibleTypeFolder`. One of these is implemented for each
 //!   folder. This defines how types of interest are folded.
 //!
@@ -72,9 +74,9 @@ pub trait TypeFoldable<I: Interner>: TypeVisitable<I> {
 
 // This trait is implemented for types of interest.
 pub trait TypeSuperFoldable<I: Interner>: TypeFoldable<I> {
-    /// Provides a default fold for a type of interest. This should only be
-    /// called within `TypeFolder` methods, when a non-custom traversal is
-    /// desired for the value of the type of interest passed to that method.
+    /// Provides a default fold for a recursive type of interest. This should
+    /// only be called within `TypeFolder` methods, when a non-custom traversal
+    /// is desired for the value of the type of interest passed to that method.
     /// For example, in `MyFolder::try_fold_ty(ty)`, it is valid to call
     /// `ty.try_super_fold_with(self)`, but any other folding should be done
     /// with `xyz.try_fold_with(self)`.
@@ -118,11 +120,11 @@ pub trait TypeFolder<I: Interner>: FallibleTypeFolder<I, Error = !> {
         t.super_fold_with(self)
     }
 
-    fn fold_region(&mut self, r: I::Region) -> I::Region
-    where
-        I::Region: TypeSuperFoldable<I>,
-    {
-        r.super_fold_with(self)
+    // The default region folder is a no-op because `Region` is non-recursive
+    // and has no `super_visit_with` method to call. That also explains the
+    // lack of `I::Region: TypeSuperFoldable<I>` bound on this method.
+    fn fold_region(&mut self, r: I::Region) -> I::Region {
+        r
     }
 
     fn fold_const(&mut self, c: I::Const) -> I::Const
@@ -167,11 +169,11 @@ pub trait FallibleTypeFolder<I: Interner>: Sized {
         t.try_super_fold_with(self)
     }
 
-    fn try_fold_region(&mut self, r: I::Region) -> Result<I::Region, Self::Error>
-    where
-        I::Region: TypeSuperFoldable<I>,
-    {
-        r.try_super_fold_with(self)
+    // The default region folder is a no-op because `Region` is non-recursive
+    // and has no `super_visit_with` method to call. That also explains the
+    // lack of `I::Region: TypeSuperFoldable<I>` bound on this method.
+    fn try_fold_region(&mut self, r: I::Region) -> Result<I::Region, Self::Error> {
+        Ok(r)
     }
 
     fn try_fold_const(&mut self, c: I::Const) -> Result<I::Const, Self::Error>
@@ -216,10 +218,7 @@ where
         Ok(self.fold_ty(t))
     }
 
-    fn try_fold_region(&mut self, r: I::Region) -> Result<I::Region, !>
-    where
-        I::Region: TypeSuperFoldable<I>,
-    {
+    fn try_fold_region(&mut self, r: I::Region) -> Result<I::Region, !> {
         Ok(self.fold_region(r))
     }
 
diff --git a/compiler/rustc_type_ir/src/visit.rs b/compiler/rustc_type_ir/src/visit.rs
index 62239fd2006..878c7aec6c1 100644
--- a/compiler/rustc_type_ir/src/visit.rs
+++ b/compiler/rustc_type_ir/src/visit.rs
@@ -13,8 +13,11 @@
 //!   - Types of interest, for which the methods delegate to the visitor.
 //!   - All other types, including generic containers like `Vec` and `Option`.
 //!     It defines a "skeleton" of how they should be visited.
-//! - `TypeSuperVisitable`. This is implemented only for each type of interest,
-//!   and defines the visiting "skeleton" for these types.
+//! - `TypeSuperVisitable`. This is implemented only for recursive types of
+//!   interest, and defines the visiting "skeleton" for these types. (This
+//!   excludes `Region` because it is non-recursive, i.e. it never contains
+//!   other types of interest.)
+//!
 //! - `TypeVisitor`. This is implemented for each visitor. This defines how
 //!   types of interest are visited.
 //!
@@ -62,12 +65,13 @@ pub trait TypeVisitable<I: Interner>: fmt::Debug + Clone {
     fn visit_with<V: TypeVisitor<I>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy>;
 }
 
+// This trait is implemented for types of interest.
 pub trait TypeSuperVisitable<I: Interner>: TypeVisitable<I> {
-    /// Provides a default visit for a type of interest. This should only be
-    /// called within `TypeVisitor` methods, when a non-custom traversal is
-    /// desired for the value of the type of interest passed to that method.
-    /// For example, in `MyVisitor::visit_ty(ty)`, it is valid to call
-    /// `ty.super_visit_with(self)`, but any other visiting should be done
+    /// Provides a default visit for a recursive type of interest. This should
+    /// only be called within `TypeVisitor` methods, when a non-custom
+    /// traversal is desired for the value of the type of interest passed to
+    /// that method. For example, in `MyVisitor::visit_ty(ty)`, it is valid to
+    /// call `ty.super_visit_with(self)`, but any other visiting should be done
     /// with `xyz.visit_with(self)`.
     fn super_visit_with<V: TypeVisitor<I>>(&self, visitor: &mut V) -> ControlFlow<V::BreakTy>;
 }
@@ -92,11 +96,11 @@ pub trait TypeVisitor<I: Interner>: Sized {
         t.super_visit_with(self)
     }
 
-    fn visit_region(&mut self, r: I::Region) -> ControlFlow<Self::BreakTy>
-    where
-        I::Region: TypeSuperVisitable<I>,
-    {
-        r.super_visit_with(self)
+    // The default region visitor is a no-op because `Region` is non-recursive
+    // and has no `super_visit_with` method to call. That also explains the
+    // lack of `I::Region: TypeSuperVisitable<I>` bound.
+    fn visit_region(&mut self, _r: I::Region) -> ControlFlow<Self::BreakTy> {
+        ControlFlow::Continue(())
     }
 
     fn visit_const(&mut self, c: I::Const) -> ControlFlow<Self::BreakTy>
diff --git a/src/librustdoc/clean/auto_trait.rs b/src/librustdoc/clean/auto_trait.rs
index 9479b3ee036..f6088f4e64a 100644
--- a/src/librustdoc/clean/auto_trait.rs
+++ b/src/librustdoc/clean/auto_trait.rs
@@ -1,7 +1,7 @@
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_hir::lang_items::LangItem;
-use rustc_middle::ty::{self, Region, RegionVid, TypeFoldable, TypeSuperFoldable};
+use rustc_middle::ty::{self, Region, RegionVid, TypeFoldable};
 use rustc_trait_selection::traits::auto_trait::{self, AutoTraitResult};
 use thin_vec::ThinVec;
 
@@ -740,10 +740,9 @@ impl<'a, 'tcx> TypeFolder<TyCtxt<'tcx>> for RegionReplacer<'a, 'tcx> {
     }
 
     fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
-        (match *r {
-            ty::ReVar(vid) => self.vid_to_region.get(&vid).cloned(),
-            _ => None,
-        })
-        .unwrap_or_else(|| r.super_fold_with(self))
+        match *r {
+            ty::ReVar(vid) => self.vid_to_region.get(&vid).cloned().unwrap_or(r),
+            _ => r,
+        }
     }
 }
diff --git a/tests/ui/rfc-2632-const-trait-impl/trait-method-ptr-in-consts-ice.rs b/tests/ui/rfc-2632-const-trait-impl/trait-method-ptr-in-consts-ice.rs
new file mode 100644
index 00000000000..7d7cb967c66
--- /dev/null
+++ b/tests/ui/rfc-2632-const-trait-impl/trait-method-ptr-in-consts-ice.rs
@@ -0,0 +1,23 @@
+// check-pass
+
+struct LazyLock<T> {
+    data: (Option<T>, fn() -> T),
+}
+
+impl<T> LazyLock<T> {
+    pub const fn new(f: fn() -> T) -> LazyLock<T> {
+        LazyLock { data: (None, f) }
+    }
+}
+
+struct A<T = i32>(Option<T>);
+
+impl<T> Default for A<T> {
+    fn default() -> Self {
+        A(None)
+    }
+}
+
+static EMPTY_SET: LazyLock<A<i32>> = LazyLock::new(A::default);
+
+fn main() {}