Update or fix LLNL toss3 PGI-18 host-config

[kennyweiss]

A recent change to LLNL's toss3 slurm has caused problems with our PGI-18 host-config.

It looks like we can do one or both of the following:

• fix the PGI-18 host-config by setting an environment variable
• upgrade the host-config to PGI-19

Details in message from Livermore Computing (LC):

A new version of LC’s affinity and binding scripts (mpibind) has been rolled out.

One of the ways that the new mpibind scripts achieve better binding is by setting ‘OMP_PROC_BIND=spread’. Unfortunately, this option is not supported by the PGI compiler until version 19.1. We have a number of older versions of the PGI compilers available on LC clusters. If you get an error about OMP_PROC_BIND, you can set ‘OMP_PROC_BIND=true’ in your environment to prevent the mpibind scripts from setting it to ‘spread’.