[llvm] [Attributor] Guard alignment query after pointer-vector stripping (PR #205389)

[Shilei Tian via llvm-commits]

shiltian wrote:

> I get this happens because <1 x ptr> is bitcastable into ptr, which is ... anyway. I left comments.

Right. That seems to be from a fuzzer. I'm wondering if we could have some better way of handling this instead of having those checks all over the place.

https://github.com/llvm/llvm-project/pull/205389