[clang] [clang][x86][bytecode] Replace interp__builtin_parity/clrsb/bitreverse/ffs with static bool interp__builtin_elementwise_int_unaryop callback (PR #162346)

[Shafik Yaghmour via cfe-commits]

================
@@ -3209,7 +3182,11 @@ bool InterpretBuiltin(InterpState &S, CodePtr OpPC, const CallExpr *Call,
   case Builtin::BI__builtin_ffs:
   case Builtin::BI__builtin_ffsl:
   case Builtin::BI__builtin_ffsll:
-    return interp__builtin_ffs(S, OpPC, Frame, Call);
+    return interp__builtin_elementwise_int_unaryop(
+        S, OpPC, Call, [](const APSInt &Val) {
----------------
shafik wrote:

My assumption was that in the `Val.reverseBits()` case it was not obvious and it was added to the others for uniformity and the fourth was accidently left out. The PR was accepted so this felt like a valid take. I would also be consistent if you removed it from all of them. 

@tbaederr how do you feel?


https://github.com/llvm/llvm-project/pull/162346