[llvm] [ValueTracking] Look through intermediate PHIs for conditional recurrences (PR #215913)

[Ömer Sinan Ağacan via llvm-commits]

https://github.com/osa1 commented:

The analysis looks reasonable, but I'm curious if it applies anywhere that matters?

If you could update your branch and resolve the conflicts (should just be a matter or renaming variables, as mentioned in inline comments) we can start a llvm-opt-benchmark-nightly run.

https://github.com/llvm/llvm-project/pull/215913