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

[Phoebe Wang via llvm-commits]

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

No special reason, just for symmetry. If we don't add subfetures, we don't disable them too. The `cf` feature does not present either.

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