[llvm] [LAA] Prepare to handle diff type sizes (NFC) (PR #122318)

[Ramkumar Ramachandra via llvm-commits]

artagnon wrote:

Ah, it is known non-positive, but not known non-negative. This is not equivalent to !(known non-zero). I would, however, argue that !(known non-zero) is the correct check, and given the current limitations, we actually should generate RT checks?

https://github.com/llvm/llvm-project/pull/122318