[llvm] [VPlan] Replicate VPScalarIVStepsRecipe by VF outside replicate regions. (PR #170053)

[via llvm-commits]

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@@ -594,12 +592,33 @@ cloneForLane(VPlan &Plan, VPBuilder &Builder, Type *IdxTy,
                                 /*IsSingleScalar=*/true, /*Mask=*/nullptr,
                                 *RepR, *RepR, RepR->getDebugLoc());
   } else {
-    assert(isa<VPInstruction>(DefR) &&
-           "DefR must be a VPReplicateRecipe or VPInstruction");
+    assert((isa<VPInstruction, VPScalarIVStepsRecipe>(DefR)) &&
+           "DefR must be a VPReplicateRecipe, VPInstruction or "
+           "VPScalarIVStepsRecipe");
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ayalz wrote:

```suggestion
```

https://github.com/llvm/llvm-project/pull/170053