[flang] Add test for allocatable on the callee side

This patch adds couple of tests for allocatable
on the callee side. Lowering for some missing underlying features
is added as well.

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

Depends on D120744

Reviewed By: PeteSteinfeld, schweitz

Differential Revision: https://reviews.llvm.org/D120746



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