[VPlan] Allow cloning of VPWidenRecipe without underlying instr (NFC).

Update VPWidenRecipe::clone() to use the constructor w/o mandatory
Instruction, to facilitate cloning VPWidenRecipe without underlying
instructions.

Split off from #148239.

Author: fhahn

llvm/lib/Transforms/Vectorize/VPlan.h

@@ -1357,9 +1357,10 @@ class LLVM_ABI_FOR_TEST VPWidenRecipe : public VPRecipeWithIRFlags,
 
 public:
   VPWidenRecipe(unsigned Opcode, ArrayRef<VPValue *> Operands,
-                const VPIRFlags &Flags, DebugLoc DL)
+                const VPIRFlags &Flags, const VPIRMetadata &Metadata,
+                DebugLoc DL)
       : VPRecipeWithIRFlags(VPDef::VPWidenSC, Operands, Flags, DL),
-        Opcode(Opcode) {}
+        VPIRMetadata(Metadata), Opcode(Opcode) {}
 
   VPWidenRecipe(Instruction &I, ArrayRef<VPValue *> Operands)
       : VPRecipeWithIRFlags(VPDef::VPWidenSC, Operands, I), VPIRMetadata(I),
@@ -1368,8 +1369,9 @@ class LLVM_ABI_FOR_TEST VPWidenRecipe : public VPRecipeWithIRFlags,
   ~VPWidenRecipe() override = default;
 
   VPWidenRecipe *clone() override {
-    auto *R = new VPWidenRecipe(*getUnderlyingInstr(), operands());
-    R->transferFlags(*this);
+    auto *R =
+        new VPWidenRecipe(getOpcode(), operands(), *this, *this, getDebugLoc());
+    R->setUnderlyingValue(getUnderlyingValue());
     return R;
   }