[llvm] [VPlan][NFC] Add cost for `VPWidenMemoryRecipe`. (PR #105614)

[Elvis Wang via llvm-commits]

================
@@ -2084,6 +2084,37 @@ void VPPredInstPHIRecipe::print(raw_ostream &O, const Twine &Indent,
 }
 #endif
 
+InstructionCost VPWidenMemoryRecipe::computeCost(ElementCount VF,
+                                                 VPCostContext &Ctx) const {
+  Instruction *I = getInstructionForCost(this);
+  Type *Ty = ToVectorTy(getElementType(), VF);
+  const Align Alignment = getLoadStoreAlignment(const_cast<Instruction *>(I));
+  const Value *Ptr = getLoadStorePointerOperand(I);
----------------
ElvisWang123 wrote:

Only ArmTTI is using the underlying IR to return different gather/scatter cost currently.

https://github.com/llvm/llvm-project/pull/105614