[llvm] [DA] Add initial support for monotonicity check (PR #162280)

[via llvm-commits]

https://github.com/amehsan commented:

On some 64-bit platform, the higher bits of address are ignored. Sometimes it is even possible to use that to store additional data (see TBI feature in AArch64). I believe in x86 we have a similar situation but the top bits need to follow a canonical form. Doesn't this allow us to assume a correct program won't have overflow in address calculation?

https://github.com/llvm/llvm-project/pull/162280