[clang] [clang] Implement `__is_layout_compatible` (PR #81506)

[Timm Baeder via cfe-commits]

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@@ -14040,6 +14040,8 @@ class Sema final {
   bool SemaValueIsRunOfOnes(CallExpr *TheCall, unsigned ArgNum);
 
 public:
+  bool SemaIsLayoutCompatible(QualType T1, QualType T2);
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tbaederr wrote:

Can this function no be `const`? And I guess the "Sema" prefix is to disambiguate with the existing `isLayoutCompatible`?

https://github.com/llvm/llvm-project/pull/81506