[llvm] [AArch64][SME2] Add ZT0 attributes to SMEAttrs (PR #77607)

[Sander de Smalen via llvm-commits]

================
@@ -2160,6 +2160,21 @@ void Verifier::verifyFunctionAttrs(FunctionType *FT, AttributeList Attrs,
            V);
   }
 
+  if (Attrs.hasFnAttr("aarch64_sme_new_zt0") ||
+      Attrs.hasFnAttr("aarch64_sme_in_zt0") ||
+      Attrs.hasFnAttr("aarch64_sme_inout_zt0") ||
+      Attrs.hasFnAttr("aarch64_sme_out_zt0") ||
+      Attrs.hasFnAttr("aarch64_sme_preserved_zt0")) {
+    Check((Attrs.hasFnAttr("aarch64_sme_new_zt0") ^
+           Attrs.hasFnAttr("aarch64_sme_in_zt0") ^
+           Attrs.hasFnAttr("aarch64_sme_inout_zt0") ^
+           Attrs.hasFnAttr("aarch64_sme_out_zt0") ^
+           Attrs.hasFnAttr("aarch64_sme_preserved_zt0")),
+          "ZT0 state attributes 'aarch64_sme_[in|inout|out|new|preserved]_zt' "
----------------
sdesmalen-arm wrote:

nit: Just write out in full:
```
"Attributes 'aarch64_new_zt0', 'aarch64_in_zt0', 'aarch64_out_zt0', 'aarch64_inout_zt0' and 'aarch64_preserves_zt0' are mutually exclusive"
```

https://github.com/llvm/llvm-project/pull/77607