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

[Alexey Bataev via llvm-commits]

================
@@ -729,6 +731,9 @@ class VPRecipeBase : public ilist_node_with_parent<VPRecipeBase, VPBasicBlock>,
       : VPDef(SC), VPUser(Operands, VPUser::VPUserID::Recipe), DL(DL) {}
   virtual ~VPRecipeBase() = default;
 
+  /// Clone the current recipe.
+  virtual VPRecipeBase *clone() { return nullptr; }
----------------
alexey-bataev wrote:

Can make it pure virtual?

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