Add specialized variants of `mk_region`.

Much like there are specialized variants of `mk_ty`. This will enable
some optimization in the next commit.

Also rename the existing `re_error*` functions as `mk_re_error*`, for
consistency.

4 files changed, 6 insertions, 7 deletions

diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs
index c12ba103c34..81ae0a3d9ba 100644
--- a/compiler/rustc_trait_selection/src/traits/object_safety.rs
+++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs
@@ -527,8 +527,7 @@ fn virtual_call_violation_for_method<'tcx>(
                 }
             }
 
-            let trait_object_ty =
-                object_ty_for_trait(tcx, trait_def_id, tcx.mk_region(ty::ReStatic));
+            let trait_object_ty = object_ty_for_trait(tcx, trait_def_id, tcx.lifetimes.re_static);
 
             // e.g., `Rc<dyn Trait>`
             let trait_object_receiver =
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index a380d4697ea..7ddffe595be 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -767,7 +767,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for BoundVarReplacer<'_, 'tcx> {
                 let universe = self.universe_for(debruijn);
                 let p = ty::PlaceholderRegion { universe, name: br.kind };
                 self.mapped_regions.insert(p, br);
-                self.infcx.tcx.mk_region(ty::RePlaceholder(p))
+                self.infcx.tcx.mk_re_placeholder(p)
             }
             _ => r,
         }
@@ -888,7 +888,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for PlaceholderReplacer<'_, 'tcx> {
                         let db = ty::DebruijnIndex::from_usize(
                             self.universe_indices.len() - index + self.current_index.as_usize() - 1,
                         );
-                        self.interner().mk_region(ty::ReLateBound(db, *replace_var))
+                        self.interner().mk_re_late_bound(db, *replace_var)
                     }
                     None => r1,
                 }
diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
index dc5bcb48cad..9770813e86d 100644
--- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
@@ -540,13 +540,13 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                                 let kind = ty::BoundRegionKind::BrNamed(param.def_id, param.name);
                                 let bound_var = ty::BoundVariableKind::Region(kind);
                                 bound_vars.push(bound_var);
-                                tcx.mk_region(ty::ReLateBound(
+                                tcx.mk_re_late_bound(
                                     ty::INNERMOST,
                                     ty::BoundRegion {
                                         var: ty::BoundVar::from_usize(bound_vars.len() - 1),
                                         kind,
                                     },
-                                ))
+                                )
                                 .into()
                             }
                             GenericParamDefKind::Const { .. } => {
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index fc9678233c3..215d39ef374 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -3023,7 +3023,7 @@ fn bind_generator_hidden_types_above<'tcx>(
                             kind: ty::BrAnon(counter, None),
                         };
                         counter += 1;
-                        r = tcx.mk_region(ty::ReLateBound(current_depth, br));
+                        r = tcx.mk_re_late_bound(current_depth, br);
                     }
                     r
                 })