[llvm] [llvm-diff] Also diff alloca's allocated type and alignment (PR #84781)

[Nikita Popov via llvm-commits]

https://github.com/nikic commented:

This looks correct, but I think it only scratches the surface of the problem? The same problem exists for load types, GEP types, and basically everything else that is checked by `hasSameSpecialState()`. Can we use that instead?

https://github.com/llvm/llvm-project/pull/84781