[clang] [llvm] [Clang][LLVM][AArch64]Add new feature SSVE-BitPerm (PR #121947)

[via llvm-commits]

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@@ -3755,7 +3755,8 @@ static const struct Extension {
     {"sve2-aes", {AArch64::FeatureAliasSVE2AES, AArch64::FeatureSVEAES}},
     {"sve2-sm4", {AArch64::FeatureSVE2SM4}},
     {"sve2-sha3", {AArch64::FeatureSVE2SHA3}},
-    {"sve2-bitperm", {AArch64::FeatureSVE2BitPerm}},
+    {"sve-bitperm", {AArch64::FeatureSVEBitPerm}},
+    {"sve2-bitperm", {AArch64::FeatureSVE2BitPerm, AArch64::FeatureSVEBitPerm}},
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Lukacma wrote:

```suggestion
    {"sve2-bitperm", {AArch64::FeatureSVE2BitPerm, AArch64::FeatureSVEBitPerm, AArch64::FeatureSVE2}},
```
I think presence of sve2 should also be changed when this feature is enabled/disabled 

https://github.com/llvm/llvm-project/pull/121947