[clang] [clang] Add tests for some of CWG issues resolved in Croydon (2026-03) (PR #189299)

[Vlad Serebrennikov via cfe-commits]

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@@ -21,3 +21,14 @@ void f(
 }
 
 } // namespace cwg3005
+
+namespace cwg3035 { // cwg3035: no
+#if __cplusplus >= 201103L
+static union {
+  int x = [] { return 42; }();
+  // FIXME-error at -1 {{lambda expressions are not allowed in anonymous unions}}
+};
+#endif
+} // namespace cwg3035
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Endilll wrote:

I added this test to `SemaCXX/lambda-expression.cpp`, which is run in C++03 mode.

https://github.com/llvm/llvm-project/pull/189299