[llvm] [VPlan] Add initial VPScalarEvolution, use to get trip count SCEV (NFC) (PR #94464)

[via llvm-commits]

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@@ -869,14 +869,23 @@ static VPIRBasicBlock *createVPIRBasicBlockFor(BasicBlock *BB) {
   return VPIRBB;
 }
 
-VPlanPtr VPlan::createInitialVPlan(const SCEV *TripCount, ScalarEvolution &SE,
+VPlanPtr VPlan::createInitialVPlan(Type *IdxTy, PredicatedScalarEvolution &PSE,
                                    bool RequiresScalarEpilogueCheck,
                                    bool TailFolded, Loop *TheLoop) {
   VPIRBasicBlock *Entry = createVPIRBasicBlockFor(TheLoop->getLoopPreheader());
   VPBasicBlock *VecPreheader = new VPBasicBlock("vector.ph");
   auto Plan = std::make_unique<VPlan>(Entry, VecPreheader);
-  Plan->TripCount =
-      vputils::getOrCreateVPValueForSCEVExpr(*Plan, TripCount, SE);
+  {
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ayalz wrote:

nit: keeping the inlined block seems a bit odd, worth unboxing, or adding a comment?

https://github.com/llvm/llvm-project/pull/94464