[llvm] [VPlan] Only store RecurKind + FastMathFlags in VPReductionRecipe. NFCI (PR #131300)

[Luke Lau via llvm-commits]

lukel97 wrote:

> FYI, I have two similar patches of changing the parent of VPReductionRecipe to VPRecipeWithIRFlags.
> 
> * [[VPlan] Change parent of VPReductionRecipe to VPRecipeWithIRFlags. NFC  #130881](https://github.com/llvm/llvm-project/pull/130881)
> * [[VPlan] Support `fast` in FMF in VPRecipeWithIRFlags. #130880](https://github.com/llvm/llvm-project/pull/130880)
> 
> My patches are focus on eliminating the dependency of the underlying instruction when printing the fastMathFlags and control the FMF by the VPRecipeWIthIRFlags, which is different to your patch that only construct the VPReductionRecipe by the RecurrenceKind.

Oh sorry I never noticed those patches! Yeah, adding the VPRecipeWIthIRFlags bit is the part that is similar here, I use it in this patch to store the FMF. I can try and stack this patch on top of #130881 then.

https://github.com/llvm/llvm-project/pull/131300