RFE: OpenCoarrays: add the oversubscribe openmpi flag in the make test phase

[jdeliacimec]

• A detailed description of your proposed feature

Following the suggestions given in the INSTALL file to build OpenCoarrays there is the line:

make test # optional; verify build works

In machines with 8 or more cores all tests are ok.
However, it would be nice if the "--oversubscribe" openmpi flag could be added in the configure or build stages for doing the same tests in machines with less than 8 cores.

The OpenCoarrys build is done with cmake in a x86_64-pc-linux-gnu machine with Fedora 36.

Many of the prerequisites were downloaded through dnf --best install, others, in particular, gcc and openmpi, were pre-built from the sources.
Two files are attached related to the configure stage of OpenMPi.

• The motivation for the feature, i.e., why would this software be better if your feature were added?

At the present time only 4% tests are passed while 82 tests failed out of 85 on machines with less than 8 cores.

• How the feature would be relevant to users (if it's not: do not open a feature request)

It would improve the dissemination of OpenCoarrays by allowing users to experiment and learn on machines with less than 8 cores having checked all the installation tests.

• What alternatives to the feature you have considered

configure.txt
machine.txt
make-test-openmpi.txt
CMakeCache.txt
openmpi-config.txt.gz
openmpi-configure.txt