[MLIR][Presburger] Inequality Typing in coalesce

This patch adds typing of inequalities to the simplex. This is a cental part of the coalesce algorithm and will be heavily used in later coalesce patches. Currently, only the three most basic types are supported with more to be introduced when they are needed.

Reviewed By: arjunp

Differential Revision: https://reviews.llvm.org/D119925