[llvm] [VPlan] Change parent of VPReductionRecipe to VPRecipeWithIRFlags. NFC (PR #130881)

[Elvis Wang via llvm-commits]

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@@ -2296,29 +2304,34 @@ class VPReductionRecipe : public VPSingleDefRecipe {
 protected:
   VPReductionRecipe(const unsigned char SC, const RecurrenceDescriptor &R,
                     Instruction *I, ArrayRef<VPValue *> Operands,
-                    VPValue *CondOp, bool IsOrdered, DebugLoc DL)
-      : VPSingleDefRecipe(SC, Operands, I, DL), RdxDesc(R),
+                    VPValue *CondOp, bool IsOrdered)
+      : VPRecipeWithIRFlags(SC, Operands, *I), RdxDesc(R),
         IsOrdered(IsOrdered) {
     if (CondOp) {
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ElvisWang123 wrote:

Oops. My bad! I didn't notice the `setUnderlyingValue()`.

But this will end up with some weird test cases.
The RecurrenceDescriptor default contains `fast` flags.  If we always set the FMF directly from recurrenceDescriptor without check if the underlyingInstruction is FPMathOperator or not, we will see `fast` on the integer reduction. 

Perhaps clear the flags carrying by the underlying instruction in the `VPReductionRecipe` and set the `FMF` if the underlying instruction is `FPMathOperator` is a better solution to avoid tests changes.

https://github.com/llvm/llvm-project/pull/130881