[llvm] [TTI] NFC: Port TLI.shouldSinkOperands to TTI (PR #110564)

[Simon Pilgrim via llvm-commits]

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@@ -6894,3 +6894,82 @@ InstructionCost X86TTIImpl::getBranchMispredictPenalty() const {
   // TODO: Hook MispredictPenalty of SchedMachineModel into this.
   return 14;
 }
+
+static bool isVectorShiftByScalarCheap(Type *Ty, const X86Subtarget *ST) {
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RKSimon wrote:

Maybe move TargetLowering::isVectorShiftByScalarCheap into TTI as well? X86 is its only user

https://github.com/llvm/llvm-project/pull/110564