[llvm] [RegAllocEvictAdvisor] Add minimum weight ratio heuristic. (PR #98109)

[Mikhail Gudim via llvm-commits]

mgudim wrote:

I've looked at the CI error - it is some assertion triggered from SLP vectorizer while compiling something in libcxx. I can't imagine how this change could trigger this, so I suspect something in the upstream is broken.

https://github.com/llvm/llvm-project/pull/98109