[clang] [AArch64][SME] Add diagnostics to CheckConstexprFunctionDefinition (PR #121777)

[Sander de Smalen via cfe-commits]

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@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -fsyntax-only -verify %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -std=c++23 -fsyntax-only -verify %s
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sdesmalen-arm wrote:

What about this change requires c++23?

https://github.com/llvm/llvm-project/pull/121777