(Reland)[mlir] Add a generic data-flow analysis framework

Removes one element of the pointer union to make it work on 32-bit
systems.

This patch introduces a generic data-flow analysis framework to MLIR. The framework implements a fixed-point iteration algorithm and a dependency graph between lattice states and analysis. Lattice states and points are fully extensible to support highly-customizable analyses.

Reviewed By: phisiart, rriddle

Differential Revision: https://reviews.llvm.org/D126751