[llvm] IR: introduce CmpInst::PredicateSign (PR #116867)

[Nikita Popov via llvm-commits]

https://github.com/nikic commented:

Two quick notes without looking into this in detail:

 * Can you please move this out of CmpInst? The fact that CmpInst::Predicate cannot be forward-declared has been a regular source of friction -- we sometimes use `unsigned` in headers just because of this. We can avoid repeating that mistake now...
 * I'm not a big fan of the name `PredicateSign`. That sounds like "the sign of the predicate" not "predicate plus samesign"...

https://github.com/llvm/llvm-project/pull/116867