[clang] [clang][C23] N3006 Underspecified object declarations (PR #79845)

[Guillot Tony via cfe-commits]

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@@ -7639,6 +7639,8 @@ def err_attribute_arm_mve_polymorphism : Error<
   "'__clang_arm_mve_strict_polymorphism' attribute can only be applied to an MVE/NEON vector type">;
 def err_attribute_webassembly_funcref : Error<
   "'__funcref' attribute can only be applied to a function pointer type">;
+def err_c23_underspecified_object_declaration: Error<
+  "'%select{struct|<ERROR>|union|<ERROR>|enum}0 %1' is defined as an underspecified object initializer">;
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to268 wrote:

I also didn't wanted to just use the same wording as GCC.

https://github.com/llvm/llvm-project/pull/79845