[clang] [Clang] Treat `ext_vector_type` as a regular type attribute (PR #130177)

[Joseph Huber via cfe-commits]

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@@ -78,7 +78,7 @@ typedef int __attribute__((ext_vector_type(0))) e4;                // expected-e
 // no support for vector enum type
 enum { e_2 } x3 __attribute__((vector_size(64))); // expected-error {{invalid vector element type}}
 
-int x4 __attribute__((ext_vector_type(64)));  // expected-error {{'ext_vector_type' attribute only applies to typedefs}}
+int x4 __attribute__((ext_vector_type(64)));
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jhuber6 wrote:

You mean add some dedicated codegen tests? I'd assume it would warn on unused, and I did check independently of this test that it gave vector output.

https://github.com/llvm/llvm-project/pull/130177