[llvm] [VPlan] Introduce VPScalarPHIRecipe, use for can & EVL IV codegen (NFC). (PR #114305)

[via llvm-commits]

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@@ -2239,6 +2239,45 @@ class VPWidenPointerInductionRecipe : public VPHeaderPHIRecipe,
 #endif
 };
 
+/// Recipe to generate a scalar PHI. Used to generate code for recipes that
+/// produce scalar header phis, including VPCanonicalIVPHIRecipe and
+/// VPEVLBasedIVPHIRecipe.
+class VPScalarPHIRecipe : public VPHeaderPHIRecipe {
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ayalz wrote:

`VPScalarHeaderPHIRecipe`?

https://github.com/llvm/llvm-project/pull/114305