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

[Mariya Podchishchaeva via cfe-commits]

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@@ -3808,13 +3867,38 @@ void Parser::ParseCXXMemberSpecification(SourceLocation RecordLoc,
   SourceLocation AbstractLoc;
   bool IsFinalSpelledSealed = false;
   bool IsAbstract = false;
+  SourceLocation TriviallyRelocatable;
+  SourceLocation Replacable;
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Fznamznon wrote:

```suggestion
  SourceLocation Replaceable;
```

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