[llvm] [VPlan] Introduce VPlanConstantFolder (PR #125365)

[Florian Hahn via llvm-commits]

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@@ -937,10 +938,84 @@ static void recursivelyDeleteDeadRecipes(VPValue *V) {
   }
 }
 
+class VPConstantFolder {
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fhahn wrote:

Would be good to document briefly.

https://github.com/llvm/llvm-project/pull/125365