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

[via llvm-commits]

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@@ -34,7 +34,7 @@ rax1 z0.d, z0.d, z0.d
 .arch_extension sve2-bitperm
 .arch_extension nosve2-bitperm
 bgrp z21.s, z10.s, z21.s
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Lukacma wrote:

I would add `.arch_extension nosve2`  to make the error message make sense. Currently for this test sve2 is enabled by tests above so the error message is confusing.

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