[clang] [Clang][SME] Add IsStreamingOrSVE2p1 (PR #75958)

[Sander de Smalen via cfe-commits]

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@@ -679,6 +679,7 @@ bool AArch64TargetInfo::hasFeature(StringRef Feature) const {
       .Case("f32mm", FPU & SveMode && HasMatmulFP32)
       .Case("f64mm", FPU & SveMode && HasMatmulFP64)
       .Case("sve2", FPU & SveMode && HasSVE2)
+      .Case("sve2p1", HasSVE2p1)
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sdesmalen-arm wrote:

It seems the changes for `HasSVE2p1` in this patch are not required for the tests to pass. I think the `hasFeature` method returns the value set by the Clang command rather than whatever is on the attribute. The `evaluateRequiredTargetFeatures` gets its information from elsewhere (not using this interface).

https://github.com/llvm/llvm-project/pull/75958