[llvm] [AArch64] Merge duplicate extension information. (PR #92319)

[Alexandros Lamprineas via llvm-commits]

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@@ -216,8 +211,10 @@ def FeaturePAN_RWV : SubtargetFeature<
 def FeaturePsUAO : SubtargetFeature< "uaops", "HasPsUAO", "true",
     "Enable v8.2 UAO PState (FEAT_UAO)">;
 
-def FeatureCCPP : SubtargetFeature<"ccpp", "HasCCPP",
-    "true", "Enable v8.2 data Cache Clean to Point of Persistence (FEAT_DPB)" >;
+let ArchExtKindSpelling = "AEK_DPB", MArchName = "dpb" in
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labrinea wrote:

I disagree with keeping AEK_CCPP. It is a made up name that doesn't match the FEAT_DPB from the architecture manual. I prefer overriding the `ArchExtKindSpelling` in the short term than having to rename all its occurences in the codebase. At least in this patch.

https://github.com/llvm/llvm-project/pull/92319