[fir] Add affine promotion pass

Convert fir operations which satisfy affine constraints to the affine
dialect.

This patch is part of the upstreaming effort from fir-dev branch.

Co-authored-by: V Donaldson <vdonaldson@nvidia.com>
Co-authored-by: Rajan Walia <walrajan@gmail.com>
Co-authored-by: Sourabh Singh Tomar <SourabhSingh.Tomar@amd.com>
Co-authored-by: Eric Schweitz <eschweitz@nvidia.com>
Co-authored-by: Valentin Clement <clementval@gmail.com>

Reviewed By: schweitz, awarzynski

Differential Revision: https://reviews.llvm.org/D111155