[libcxx-commits] [libcxx] [libc++] Fix broken precondition of __bit_log2 (PR #155476)

[Louis Dionne via libcxx-commits]

ldionne wrote:

I'm going to merge this so we can get started with the cherry-pick ASAP. This seemingly innocent change had significant fallout and I think we definitely want that fixed in the release.

If we need to do additional follow-ups to get consensus, I'm fine with that, but as-is this prevents us from violating one of our own function's preconditions, so I think it's reasonable.

https://github.com/llvm/llvm-project/pull/155476