[llvm] [VPlan] Replace all uses of VF when EVL tail folding. NFCI (PR #146339)

[Luke Lau via llvm-commits]

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@@ -2198,6 +2198,10 @@ static void transformRecipestoEVLRecipes(VPlan &Plan, VPValue &EVL) {
   VPRegionBlock *LoopRegion = Plan.getVectorLoopRegion();
   VPBasicBlock *Header = LoopRegion->getEntryBasicBlock();
 
+  assert(all_of(Plan.getVF().users(),
+                IsaPred<VPVectorEndPointerRecipe, VPScalarIVStepsRecipe>));
+  Plan.getVF().replaceAllUsesWith(&EVL);
+
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lukel97 wrote:

We need to move this above the FOR transform because it introduces a trunc that uses the original VF

https://github.com/llvm/llvm-project/pull/146339