hera.gnu config & selective merge of UFS public release hotfix to develop (fixes problem with MPI_Comm_Split in openmpi when hash is negative)

[climbfuji]

See update in comment further down!

This PR adds support for hera.gnu to the NEMS build system and merges two commits from the UFS public release branch to develop, required for using OpenMPI with the GNU compilers on Hera: 5434d8e and e84f1b9. See original PR #25 for the UFS public release branch (from @mark-a-potts).

Associated PRs:

#43
NCAR/ccpp-physics#409
NCAR/fv3atm#31
NCAR/ufs-weather-model#28

For regression testing info, see NCAR/ufs-weather-model#28.

This PR can be merged into develop without restriction, even though all associated PRs are going to NCAR's dtc/develop first (independent change), provided that the regression tests described above all pass.

[grantfirl]

Approved.

[climbfuji]

Update 2020/03/17. This PR now needs to be merged as part of these PRs:

Associated PRs:

#43
NCAR/ccpp-physics#410
NCAR/ccpp-framework#268
NOAA-EMC/ufsatm#81
ufs-community/ufs-weather-model#84

See ufs-community/ufs-weather-model#84 for regression testing information.

[climbfuji]

@junwang-noaa @DusanJovic-NOAA @RatkoVasic-NOAA @MinsukJi-NOAA

[junwang-noaa]

@junwang-noaa @DusanJovic-NOAA @RatkoVasic-NOAA @MinsukJi-NOAA

I think this can be committed after full RT is done with ufs-weather-model PR

[MinsukJi-NOAA]

@junwang-noaa @DusanJovic-NOAA @RatkoVasic-NOAA @MinsukJi-NOAA

I think this can be committed after full RT is done with ufs-weather-model PR

Full RT (both NEMSCompsetRun and rt.sh) with ufs-weather-model PR (ufs-community/ufs-weather-model#84) all passed on Hera:
Compile_hera.intel.log
RegressionTests_hera.intel.log
rtreport.txt

[climbfuji]

Great, thank you! I also ran the rt.sh and NEMSCompsetRun tests on hera with Intel. I have already updated the rt.sh regression test logs in the PR, will update the NEMSCompsetRun logs in a minute. Thanks for doing this, highly appreciated.