[llvm] [clang] [ValueTracking] Add dominating condition support in computeKnownBits() (PR #73662)

[Nikita Popov via cfe-commits]

nikic wrote:

> Just realized that this doesn't cover uses of isKnownNonNegative() in InstCombine yet, as it currently doesn't go through SimplifyQuery. I'll see about migrating those APIs tomorrow.

This is done now, but introduced an additional regression in idioms.ll.

https://github.com/llvm/llvm-project/pull/73662