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

[Kerry McLaughlin via cfe-commits]

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@@ -1328,4 +1328,57 @@ void SemaARM::handleInterruptAttr(Decl *D, const ParsedAttr &AL) {
                  ARMInterruptAttr(getASTContext(), AL, Kind));
 }
 
+// Check if the function definition uses any AArch64 SME features without
+// having the '+sme' feature enabled and warn user if sme locally streaming
+// function returns or uses arguments with VL-based types.
+void SemaARM::CheckSMEFunctionDefAttributes(const FunctionDecl *FD) {
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kmclaughlin-arm wrote:

I've changed this to `static` and added `Sema` as a parameter, so that the function can still use `Diag()` for emitting the diagnostics.

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