[clang] [clang] Add tests for CWG issues regarding completeness of types (PR #92113)

[Shafik Yaghmour via cfe-commits]

================
@@ -451,6 +463,25 @@ static_assert(!__is_nothrow_constructible(D4, int), "");
 #endif
 } // namespace cwg1350
 
+namespace cwg1352 { // cwg1352: 3.0
+struct A {
+#if __cplusplus >= 201103L
+  int a = sizeof(A);
----------------
shafik wrote:

I think it might be worth it to see that this fails for a `static member` since the DR specifically says `non-static` so we should cover both.

https://github.com/llvm/llvm-project/pull/92113