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

[Nikita Popov via llvm-commits]

nikic wrote:

> > As a side note, we should really replace this argument with an `align` attribute on the pointer parameter...
> 
> Yeah, I was wondering why it was needed since the `compress` and `expand` variants don't use it. I'm guessing that would need some auto-upgrade handling or something.

Right. We've done this change for the memcpy etc intrinsics in the past: https://github.com/llvm/llvm-project/blob/d39772cb053c194ef809f3ca765f37237c4e1956/llvm/lib/IR/AutoUpgrade.cpp#L5100-L5133

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