Fix send_by_ref by modelling it like get_by_ref.

[vehre]

coverage on master

Summary of changes

Send_by_ref was working as expected for static arrays and arrays of higher rank.

Rationale for changes

Make send_by_ref to work for static arrays and arrays of higher rank. This fixes #654.

Additional info and certifications

This pull request (PR) is a:

• Bug fix
• Feature addition
• Other, Please describe:

I certify that

• I certify that:
  • I have reviewed and followed the contributing guidelines
  • I will wait at least 24 hours before self-approving the PR to give another
    OpenCoarrays developer a chance to review my proposed code
  • I have not introduced errant white space (no trailing white space or white space errors may
    be introduced)
  • I have added an explanation of what these changes do and why they should be included
  • I have checked to ensure there aren't other open Pull Requests for the same change
  • I have you written new tests for these changes
  • I have successfully tested these changes locally
  • I have commented any non-trivial, non-obvious code changes
  • The commits are logically atomic, self consistent and coherent
  • The commit messages follow best practices
  • Test coverage is maintained or increased after this is merged

Code coverage data

[vehre]

This fix also fixes the last open testsuite failure get_static_array.f90. It was tested with mpich 4.1.2, openmpi 4.1.5 and intel mpi 2021.13.

[vehre]

@zbeekman or @rouson can you please review?

[zbeekman]

@vehre a few questions, please see my comments. Sorry this sat for so long.

[zbeekman]

@vehre do you know what's going on with the build errors? I don't have time to take a look at what it will take to resolve them at the moment.

[vehre]

I'll take a look tomorrow.

[vehre]

@zbeekman Sorry for all the email noise, but I had to figure the CIs. I think, I got them as usable as possible now. Fact is:

• mpich is b0rken on ubuntu-latest aka 24.04LTS and no other runners available
• openmpi is b0rken on ubuntu-latest aka 24.04LTS and no other runners available

This means we are stuck with Intel's mpi on Linux and Windows. But both of these CIs run. With more recent mpi versions on Linux all tests pass on my system.

[zbeekman]

@vehre what an annoying set of bugs, thanks for fixing this!

I might test out reverting Ubuntu to 22.04 to see if it's possible to test with another mpi as well. If it doesn't work I will keep what you have here.

[zbeekman]

Looks good to me! I might try to convince CI to run using Ubuntu 22.04 on linux, but if I don't have success I will just merge what's here and call it good.

[vehre]

@zbeekman I have added a workflow for ubuntu-22.04 for mpich and impi. Openmpi is also b0rken on ubuntu 22.04.