[flang] Add more lowering tests for dummy arguments

This patch adds more lowering tests for dummy arguments
and adds lowering for a specific case.

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

Reviewed By: schweitz

Differential Revision: https://reviews.llvm.org/D121919



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