[llvm] [VPlan] Verify dominance for incoming values of phi-like recipes. (PR #124838)

[Florian Hahn via llvm-commits]

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@@ -3283,6 +3295,48 @@ class VPScalarIVStepsRecipe : public VPRecipeWithIRFlags,
   }
 };
 
+/// Casting from VPRecipeBase -> VPPhiAccessors is supported for all recipe
+/// types implementing VPPhiAccessors.
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fhahn wrote:

Yep as there's no link between RecipeBase and VPPhiAccessors. `CastIsPossible`  is used for `isa`

https://github.com/llvm/llvm-project/pull/124838