Normalize opaques with escaping bound vars

compiler/rustc_trait_selection/src/traits/project.rs

@@ -500,10 +500,7 @@ impl<'a, 'b, 'tcx> TypeFolder<TyCtxt<'tcx>> for AssocTypeNormalizer<'a, 'b, 'tcx
         // to make sure we don't forget to fold the substs regardless.
 
         match kind {
-            // This is really important. While we *can* handle this, this has
-            // severe performance implications for large opaque types with
-            // late-bound regions. See `issue-88862` benchmark.
-            ty::Opaque if !data.substs.has_escaping_bound_vars() => {
+            ty::Opaque => {
                 // Only normalize `impl Trait` outside of type inference, usually in codegen.
                 match self.param_env.reveal() {
                     Reveal::UserFacing => ty.super_fold_with(self),
@@ -529,7 +526,6 @@ impl<'a, 'b, 'tcx> TypeFolder<TyCtxt<'tcx>> for AssocTypeNormalizer<'a, 'b, 'tcx
                     }
                 }
             }
-            ty::Opaque => ty.super_fold_with(self),
 
             ty::Projection if !data.has_escaping_bound_vars() => {
                 // This branch is *mostly* just an optimization: when we don't

compiler/rustc_trait_selection/src/traits/query/normalize.rs

@@ -211,10 +211,7 @@ impl<'cx, 'tcx> FallibleTypeFolder<TyCtxt<'tcx>> for QueryNormalizer<'cx, 'tcx>
 
         // Wrap this in a closure so we don't accidentally return from the outer function
         let res = match kind {
-            // This is really important. While we *can* handle this, this has
-            // severe performance implications for large opaque types with
-            // late-bound regions. See `issue-88862` benchmark.
-            ty::Opaque if !data.substs.has_escaping_bound_vars() => {
+            ty::Opaque => {
                 // Only normalize `impl Trait` outside of type inference, usually in codegen.
                 match self.param_env.reveal() {
                     Reveal::UserFacing => ty.try_super_fold_with(self)?,
@@ -255,8 +252,6 @@ impl<'cx, 'tcx> FallibleTypeFolder<TyCtxt<'tcx>> for QueryNormalizer<'cx, 'tcx>
                 }
             }
 
-            ty::Opaque => ty.try_super_fold_with(self)?,
-
             ty::Projection | ty::Inherent | ty::Weak => {
                 // See note in `rustc_trait_selection::traits::project`