[Chapel Merge] Small updates in support of the prebuilt module fo

Branch: refs/heads/1.23-for-EX
Revision: 4706bf3
Author: gbtitus
Log Message:

Merge pull request #16685 from gbtitus/dup-0a34034

Small updates in support of the prebuilt module for EX systems.

(Duplicate PR #16569 from master to 1.23-for-EX.)

(Original PR reviewed by @ronawho.)

This is a collection of small changes in support of the EX module.

Use a ‘system’ libfabric and enable finding one with pkg-config.

Generate code for the Rome processor, which is our x86 least common
denominator CPU (for now) for EX systems.

Use gcc 10 for the gcc target compiler. This is new enough to support
the Rome processor. Relatedly, make some minor adjustments to how we
declare variables global to all the comm=ofi source files.

Update the command line we give to the PALS launcher, when that is in
use.

Add CHPL_LAUNCHER=none to the built configurations, which as a side
effect also enables PIC builds which are only used for on login nodes,
with launcher=none and comm=none.

Modified Files:
M runtime/src/comm/ofi/comm-ofi-internal.h
M runtime/src/comm/ofi/comm-ofi.c
M runtime/src/launch/pals/pals-utils.c
M util/build_configs/cray-internal/setenv-hpe-cray-ex-x86_64.bash

Compare: https://github.com/chapel-lang/chapel/compare/9ad76332044a...4706bf36b51a