[llvm] [ConstraintElim] Add facts implied by llvm.abs (PR #73189)

[Alexander Shaposhnikov via llvm-commits]

alexander-shaposhnikov wrote:

@dtcxzyw  - yes, llvm.abs calls originate e.g. from std::abs and this showed up multiple times when i was testing the patch internally.

https://github.com/llvm/llvm-project/pull/73189