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

[Luke Lau via llvm-commits]

lukel97 wrote:

> I think
> 
> > > LGTM, as long as it doesn't complicate #113903
> > 
> > 
> > I'm not in a rush so I can wait until #113903 lands first, and then I can rebase this on top of it @ElvisWang123
> 
> Just looked and if that type is the only thing that needs storing in #113903 I think it should be fine to merge this one now

Ok, I'll land this now then and it get it out of the way

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