[llvm] [VPlan] Model branch cond to enter scalar epilogue in VPlan. (PR #92651)

[via llvm-commits]

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@@ -784,8 +821,9 @@ VPlan::~VPlan() {
 }
 
 VPlanPtr VPlan::createInitialVPlan(const SCEV *TripCount, ScalarEvolution &SE,
-                                   BasicBlock *PH) {
-  VPIRBasicBlock *Preheader = new VPIRBasicBlock(PH);
+                                   bool RequiresScalarEpilogueCheck,
+                                   bool TailFolded, Loop *TheLoop) {
+  VPIRBasicBlock *Preheader = new VPIRBasicBlock(TheLoop->getLoopPreheader());
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ayalz wrote:

nit (independent of this patch): `Preheader` is ambiguous, better renamed `Entry` following our roadmap https://llvm.org/devmtg/2023-10/slides/techtalks/Hahn-VPlan-StatusUpdateAndRoadmap.pdf#page=37

https://github.com/llvm/llvm-project/pull/92651