[llvm] [LoopVectorizer] Prune VFs based on plan register pressure (PR #132190)

[Sam Tebbs via llvm-commits]

SamTebbs33 wrote:

> It would be great to check the perf-impact on some benchmarks on AArch64, just to double check there are no unexpected regressions.

I've done some measuring with an industry-leading benchmark suite and there haven't been any regressions thankfully.

https://github.com/llvm/llvm-project/pull/132190