[llvm] [VPlan] Track VPValues instead of VPRecipes in calculateRegisterUsage. (PR #155301)

[Luke Lau via llvm-commits]

https://github.com/lukel97 commented:

Makes sense to me. Generally I'm seeing improvements on RISC-V, but I'm also seeing more spills on imagick_r from SPEC CPU 2017.

I think there might be strided accesses that are lowered as intereleaved groups where some groups are dead, and we're not taking that into account?

https://github.com/llvm/llvm-project/pull/155301