[clang] [Clang][Sema] fix crash of attribute transform (PR #78088)

[Qizhi Hu via cfe-commits]

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@@ -6124,7 +6124,11 @@ QualType TreeTransform<Derived>::TransformFunctionProtoType(
       //   "pointer to cv-qualifier-seq X" between the optional cv-qualifer-seq
       //   and the end of the function-definition, member-declarator, or
       //   declarator.
-      Sema::CXXThisScopeRAII ThisScope(SemaRef, ThisContext, ThisTypeQuals);
+      auto *RD =
+          dyn_cast_or_null<CXXRecordDecl>(SemaRef.getCurLexicalContext());
+      Sema::CXXThisScopeRAII ThisScope(
+          SemaRef, ThisContext == nullptr && nullptr != RD ? RD : ThisContext,
+          ThisTypeQuals);
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jcsxky wrote:

Code Fixed and release note has been added.

https://github.com/llvm/llvm-project/pull/78088