[llvm] [InstCombine] Always fold nonnull assumptions into operand bundles (PR #169923)

[Nikita Popov via llvm-commits]

https://github.com/nikic approved this pull request.

LGTM

Based on llvm-opt-benchmark, one of the big impacts of this change is that we retain nonnull assumptions that were previously eliminated by SCCP/CVP based on dominating information. Similarly to https://github.com/llvm/llvm-project/pull/183688#pullrequestreview-3872544742, I'm inclined to say that this is the behavior we want, as assumes only eliminated by SCCP/CVP (but not VT) are probably not sufficiently trivial as to be considered redundant. If we do see issues with too many assumes being retained, we can always adjust those passes to also remove nonnull assumes. Let's give this a try.

https://github.com/llvm/llvm-project/pull/169923