rename PointerKind::Shared → SharedMutable to indicate this is NOT the usual shared reference

Author: RalfJung

compiler/rustc_middle/src/ty/layout.rs

@@ -2618,14 +2618,14 @@ where
                     // Use conservative pointer kind if not optimizing. This saves us the
                     // Freeze/Unpin queries, and can save time in the codegen backend (noalias
                     // attributes in LLVM have compile-time cost even in unoptimized builds).
-                    PointerKind::Shared
+                    PointerKind::SharedMutable
                 } else {
                     match mt {
                         hir::Mutability::Not => {
                             if ty.is_freeze(tcx.at(DUMMY_SP), cx.param_env()) {
                                 PointerKind::Frozen
                             } else {
-                                PointerKind::Shared
+                                PointerKind::SharedMutable
                             }
                         }
                         hir::Mutability::Mut => {
@@ -2636,7 +2636,7 @@ where
                             if ty.is_unpin(tcx.at(DUMMY_SP), cx.param_env()) {
                                 PointerKind::UniqueBorrowed
                             } else {
-                                PointerKind::Shared
+                                PointerKind::SharedMutable
                             }
                         }
                     }
@@ -3285,7 +3285,7 @@ impl<'tcx> LayoutCx<'tcx, TyCtxt<'tcx>> {
                     // or not to actually emit the attribute. It can also be controlled with the
                     // `-Zmutable-noalias` debugging option.
                     let no_alias = match kind {
-                        PointerKind::Shared | PointerKind::UniqueBorrowed => false,
+                        PointerKind::SharedMutable | PointerKind::UniqueBorrowed => false,
                         PointerKind::UniqueOwned => noalias_for_box,
                         PointerKind::Frozen => !is_return,
                     };

compiler/rustc_target/src/abi/mod.rs

@@ -1350,7 +1350,7 @@ impl<'a, Ty> Deref for TyAndLayout<'a, Ty> {
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
 pub enum PointerKind {
     /// Most general case, we know no restrictions to tell LLVM.
-    Shared,
+    SharedMutable,
 
     /// `&T` where `T` contains no `UnsafeCell`, is `noalias` and `readonly`.
     Frozen,