workflow: add MacOS compile check

[wenduwan]

Increase CI coverage to prevent #12693

[wenduwan]

FYI @dalcinl I copied your setup script from https://github.com/mpi4py/mpi-publish/blob/master/.github/workflows/cd-wheel.yml#L126

I believe our licenses are compatible.

[dalcinl]

@wenduwan Why did you call the workflow file compile-macos-intel.yaml ? You should remove the -intel suffix.

[wenduwan]

Thanks @dalcinl and @jsquyres . Based on what I'm hearing, I think what we really want is to test on the latest macOS, regardless of the underlying architecture. This simplifies the workflow a bit.

Also added make parallelization as Lisandro suggested.

[dalcinl]

@wenduwan Is there any quick make check or make test that you could run (after a make install) to make sure that the thing you just built is actually usable at runtime?

[wenduwan]

@dalcinl Good question. I think we might need to run something close to the mpi4py suite in order to have some reasonable coverage.

@jsquyres I wonder what should be our "minimal" coverage on mac?

[jsquyres]

@wenduwan Wouldn't be a bad thing to do a make check (which runs a bunch of unit tests) and maybe then also a make in the examples directory and does an mpirun -np NUM_CORES on each of the executables (hello world and ring in the different bindings).

I wouldn't worry too much about make distcheck -- we test that in Linux, and a) that's a good indicator that it will (probably) also work on MacOS, and b) we realistically rarely invoke make distcheck on MacOS anyway.

[jsquyres]

It only runs a single ring_c test, but that's good enough for now (i.e., it's good enough as a sanity test). Let's merge this now and add more macos testing over time.