[llvm] [VPlan] Implement cloning of VPlans. (PR #73158)

[Alexey Bataev via llvm-commits]

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@@ -1086,6 +1097,13 @@ class VPInstruction : public VPRecipeWithIRFlags, public VPValue {
 
   VP_CLASSOF_IMPL(VPDef::VPInstructionSC)
 
+  virtual VPRecipeBase *clone() override {
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alexey-bataev wrote:

Drop virtual?

https://github.com/llvm/llvm-project/pull/73158