[clang] [llvm] [compiler-rt] [AArch64][SME] Add support for sme-fa64 (PR #70809)

[Sander de Smalen via cfe-commits]

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@@ -162,6 +163,7 @@ enum ArchExtKind : unsigned {
   AEK_FPMR =          58, // FEAT_FPMR
   AEK_FP8 =           59, // FEAT_FP8
   AEK_FAMINMAX =      60, // FEAT_FAMINMAX
+  AEK_SMEFA64 =       61, // FEAT_SMEFA64
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sdesmalen-arm wrote:

nit: can you define this after `AEK_SME`? The feature is part of SME(1), so at least that way we keep the definitions together in this enum.

https://github.com/llvm/llvm-project/pull/70809