[llvm] [ConstraintElimination] Add eq/ne facts to signed constraint system (PR #121423)

[Nikita Popov via llvm-commits]

nikic wrote:

> I'm thinking if we can only add facts to signed system only for eq, but not ne, at line 1598, to avoid unnecessary `getConstraint` & `decompose` for ne cases to save compiling time, as ne cannot be handled for signed system for now.

An early exit for ne constraints where not supported makes sense to me. Do you plan to submit a patch for this?

https://github.com/llvm/llvm-project/pull/121423