[clang] [clang][FMV] Do not omit explicit default target_version attribute. (PR #96628)

[Tomas Matheson via cfe-commits]

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@@ -102,8 +102,9 @@ int __attribute__((target_version("sha2"))) combine(void) { return 1; }
 // expected-error at +1 {{multiversioned function declaration has a different calling convention}}
 int __attribute__((aarch64_vector_pcs, target_version("sha3"))) combine(void) { return 2; }
 
-int __attribute__((target_version("fp+aes+pmull+rcpc"))) unspec_args() { return -1; }
+int unspec_args();
 // expected-error at -1 {{multiversioned function must have a prototype}}
-// expected-error at +1 {{multiversioned function must have a prototype}}
+// expected-note at +1 {{function multiversioning caused by this declaration}}
+int __attribute__((target_version("fp"))) unspec_args() { return -1; }
 int __attribute__((target_version("default"))) unspec_args() { return 0; }
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tmatheson-arm wrote:

Can we keep the test to check that we _don't_ emit a diagnostic then?

https://github.com/llvm/llvm-project/pull/96628