[fir] Add array value copy pass

This patch upstream the array value copy pass.

Transform the set of array value primitives to a memory-based array
representation.

The Ops `array_load`, `array_store`, `array_fetch`, and `array_update` are
used to manage abstract aggregate array values. A simple analysis is done
to determine if there are potential dependences between these operations.
If not, these array operations can be lowered to work directly on the memory
representation. If there is a potential conflict, a temporary is created
along with appropriate copy-in/copy-out operations. Here, a more refined
analysis might be deployed, such as using the affine framework.

This pass is required before code gen to the LLVM IR dialect.

This patch is part of the upstreaming effort from fir-dev branch. The
pass is bringing quite a lot of file with it.

Reviewed By: kiranchandramohan, schweitz

Differential Revision: https://reviews.llvm.org/D111337



Co-authored-by: Jean Perier <jperier@nvidia.com>
Co-authored-by: Eric Schweitz <eschweitz@nvidia.com>
Co-authored-by: V Donaldson <vdonaldson@nvidia.com>