[clang] [X86] Support apxf in attribute target (PR #184078)

[Phoebe Wang via cfe-commits]

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@@ -179,6 +179,31 @@ bool X86TargetInfo::initFeatureMap(
       continue;
     }
 
+    // Expand apxf to the individual APX features
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phoebewang wrote:

This duplicates the expansion of apxf in the driver. Shoud be better remove that part?

https://github.com/llvm/llvm-project/pull/184078