[clang] [Clang][Sema]: Allow flexible arrays in unions and alone in structs (PR #84428)

[Nick Desaulniers via cfe-commits]

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@@ -0,0 +1,43 @@
+// RUN: %clang_cc1 %s -verify=c -fsyntax-only -fflex-array-extensions
+
+// The test checks that flexible array members do not emit warnings when
+// -fflex-array-extensions when used in a union or alone in a structure.
+
+struct already_hidden {
+	int a;
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nickdesaulniers wrote:

Please run `git clang-format HEAD~` on  your commit. This looks like kernel coding style and not llvm coding style (which is used even for unit tests).

https://github.com/llvm/llvm-project/pull/84428