[clang] [Clang] Implement CWG2496 (PR #142975)

[Vlad Serebrennikov via cfe-commits]

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@@ -215,3 +215,23 @@ void (*q)() throw() = S();
 // since-cxx17-error at -1 {{no viable conversion from 'S' to 'void (*)() throw()'}}
 //   since-cxx17-note@#cwg2486-conv {{candidate function}}
 } // namespace cwg2486
+
+
+namespace cwg2496 { // cwg2496: 21
+#if __cplusplus >= 201102L
+struct S {
+    virtual void f(); // expected-note {{previous declaration is here}}
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Endilll wrote:

Leave a bookmark here, and move the notes after their respective errors

https://github.com/llvm/llvm-project/pull/142975