[clang] [llvm] [AArch64] Reduce +sve2-aes to an alias of +sve-aes+sve2 (PR #114293)

[via cfe-commits]

================
@@ -369,9 +369,12 @@ def FeatureSVE2 : ExtensionWithMArch<"sve2", "SVE2", "FEAT_SVE2",
   "Enable Scalable Vector Extension 2 (SVE2) instructions",
   [FeatureSVE, FeatureUseScalarIncVL]>;
 
-def FeatureSVE2AES : ExtensionWithMArch<"sve2-aes", "SVE2AES",
+def FeatureSVEAES : ExtensionWithMArch<"sve-aes", "SVEAES",
   "FEAT_SVE_AES, FEAT_SVE_PMULL128",
-  "Enable AES SVE2 instructions", [FeatureSVE2, FeatureAES]>;
+  "Enable SVE AES and 128-bit PMULL instructions", [FeatureAES]>;
+
+def FeatureSVE2AES : ExtensionWithMArch<"sve2-aes", "SVE2AES", "",
----------------
Lukacma wrote:

I think we should also get rid of HasSVE2AES in backend and replace it with HasSVE2, HasSVEAES (which would need creating). This would of course require modifying the backend tests for these instructions, testing both with` -mattr=+sve2,+sve-aes` and `-mattr=+sve-aes2`

https://github.com/llvm/llvm-project/pull/114293