[clang] [Clang] Implement the core language parts of P2786 - Trivial relocation (PR #127636)

[via cfe-commits]

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@@ -127,6 +127,33 @@ class AccessSpecDecl : public Decl {
   static bool classofKind(Kind K) { return K == AccessSpec; }
 };
 
+enum class RelocatableOrReplaceableClassSpecifierKind {
+  Relocatable,
+  Replaceable
+};
+
+template <RelocatableOrReplaceableClassSpecifierKind MK>
+class BasicRelocatableOrReplaceableClassSpecifier {
+public:
+  BasicRelocatableOrReplaceableClassSpecifier() = default;
+  BasicRelocatableOrReplaceableClassSpecifier(SourceLocation Begin)
+      : Loc(Begin) {}
+  void Set(SourceLocation Begin) { Loc = Begin; }
+
+  bool isSet() const { return !Loc.isInvalid(); }
+
+  SourceLocation getLocation() const { return Loc; }
+
+private:
+  SourceLocation Loc;
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cor3ntin wrote:

It used to have more. But I kept it because I felt a string type was cleaner than a bunch of lone SourceLocations. I'd rather keep it, unless you feel strongly about it

https://github.com/llvm/llvm-project/pull/127636