[llvm] [PowerPC] clean unused PPC target feature FeatureBPERMD (PR #159782)

[Sergei Barannikov via llvm-commits]

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@@ -377,7 +375,7 @@ def NoNaNsFPMath
     : Predicate<"Subtarget->getTargetMachine().Options.NoNaNsFPMath">;
 def NaNsFPMath
     : Predicate<"!Subtarget->getTargetMachine().Options.NoNaNsFPMath">;
-def HasBPERMD : Predicate<"Subtarget->hasBPERMD()">;
+def HasBPERMD : Predicate<"Subtarget->getCPUDirective() >= PPC::DIR_PWR7">;
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s-barannikov wrote:

Should it instead add AssemblerPredicate to make sure the instructions are not assembled/disassembled without the feature enabled?

https://github.com/llvm/llvm-project/pull/159782