[clang] [clang][AArch64] Add getHostCPUFeatures to query for enabled features in cpu info (PR #97749)

[Tomas Matheson via cfe-commits]

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@@ -445,4 +445,21 @@ void aarch64::getAArch64TargetFeatures(const Driver &D,
 
   if (Args.getLastArg(options::OPT_mno_bti_at_return_twice))
     Features.push_back("+no-bti-at-return-twice");
+
+  // Parse AArch64 CPU Features
+  const Arg *CPUArg = Args.getLastArg(options::OPT_mcpu_EQ);
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tmatheson-arm wrote:

Feels like this should be done in `getAArch64ArchFeaturesFromMcpu`/`DecodeAArch64Mcpu`

https://github.com/llvm/llvm-project/pull/97749