[llvm] [InstCombine] Simplify select using KnownBits of condition (PR #95923)

[via llvm-commits]

goldsteinn wrote:

> Okay, it seems like the "adding member causes significant compile time regression" is some kind of gcc optimization fluke.

Any thoughts on switching to LLVM as the default compiler?

https://github.com/llvm/llvm-project/pull/95923