Auto merge of #108020 - nnethercote:opt-mk_region, r=compiler-errors

Optimize `mk_region`

PR #107869 avoiding some interning under `mk_ty` by special-casing `Ty` variants with simple (integer) bodies. This PR does something similar for regions.

r? `@compiler-errors`

1 files changed, 2 insertions, 3 deletions

diff --git a/compiler/rustc_ty_utils/src/abi.rs b/compiler/rustc_ty_utils/src/abi.rs
index ad5527f5a77..03025e186b3 100644
--- a/compiler/rustc_ty_utils/src/abi.rs
+++ b/compiler/rustc_ty_utils/src/abi.rs
@@ -70,7 +70,7 @@ fn fn_sig_for_fn_abi<'tcx>(
                 var: ty::BoundVar::from_usize(bound_vars.len() - 1),
                 kind: ty::BoundRegionKind::BrEnv,
             };
-            let env_region = ty::ReLateBound(ty::INNERMOST, br);
+            let env_region = tcx.mk_re_late_bound(ty::INNERMOST, br);
             let env_ty = tcx.closure_env_ty(def_id, substs, env_region).unwrap();
 
             let sig = sig.skip_binder();
@@ -95,8 +95,7 @@ fn fn_sig_for_fn_abi<'tcx>(
                 var: ty::BoundVar::from_usize(bound_vars.len() - 1),
                 kind: ty::BoundRegionKind::BrEnv,
             };
-            let env_region = ty::ReLateBound(ty::INNERMOST, br);
-            let env_ty = tcx.mk_mut_ref(tcx.mk_region(env_region), ty);
+            let env_ty = tcx.mk_mut_ref(tcx.mk_re_late_bound(ty::INNERMOST, br), ty);
 
             let pin_did = tcx.require_lang_item(LangItem::Pin, None);
             let pin_adt_ref = tcx.adt_def(pin_did);