[clang] [llvm] [AArch64] Split FeatureLS64 to LS64_ACCDATA and LS64_V. (PR #101712)

[Tomas Matheson via cfe-commits]

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@@ -305,9 +305,17 @@ def FeatureWFxT : ExtensionWithMArch<"wfxt", "WFxT", "FEAT_WFxT",
 def FeatureHCX : Extension<"hcx", "HCX", "FEAT_HCX",
   "Enable Armv8.7-A HCRX_EL2 system register">;
 
-def FeatureLS64 : ExtensionWithMArch<"ls64", "LS64",
-  "FEAT_LS64, FEAT_LS64_V, FEAT_LS64_ACCDATA",
-  "Enable Armv8.7-A LD64B/ST64B Accelerator Extension">;
+def FeatureLS64 : Extension<"ls64", "LS64", "FEAT_LS64",
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tmatheson-arm wrote:

The internal feature name `+ls64` would need to be something like `+ls64only` to preserve backwards compatibility of the IR.

https://github.com/llvm/llvm-project/pull/101712