[llvm] [InferAlignment] Increase alignment in masked load / store instrinsics if known (PR #156057)

[Joseph Huber via llvm-commits]

jhuber6 wrote:

Thanks for reporting, seems your case causes it to think the alignment is `-1` which rounds to `0` when set, which isn't considered valid. I think infinite alignment shows up on null pointers, so I probably need to verify that and not update it.

https://github.com/llvm/llvm-project/pull/156057