Add GNU compiler flags to help build with GNU v10 and above

[ndkeen]

Specifically, adding -fallow-argument-mismatch -fallow-invalid-boz for any GNU build using version 10 or higher.

Fixes #3954

[bfb]

[jayeshkrishna]

We also found that we needed the "-fallow-argument-mismatch" flag for building SCORPIO with gnu 11

[ndkeen]

I suspect you need it for GNU v10 as well

[ndkeen]

Note it seems like these are work-around flags and there may be other ways to address. Or... we could only compile certain files (or components) with these flags.

The -fallow-argument-mismatch flag is used to make these warnings instead of errors (in cime/src/share/timing/perf_utils.F90 for example):

   22 |     call MPI_BCAST(vec,lsize,MPI_INTEGER,0,comm,ierr)
      |                   1
......
   31 |     call MPI_BCAST(vec,lsize,MPI_LOGICAL,0,comm,ierr)
      |                   2
Error: Type mismatch between actual argument at (1) and actual argument at (2) (INTEGER(4)/LOGICAL(4)).

The -fallow-invalid-boz flag is actually only needed for 2 places in e3sm:
In components/eam/src/control/cam_history.F90, there is this line:
integer, parameter :: gen_hash_key_offset = z'000053db'
And in elm/src/biogeochem/MEGANFactorsMod.F90 there is something similar.

Which looks to be used to init a hash before adding values. Not familiar with algorithm there, but perhaps there is way to change the code instead of using that flag.

I'm testing with adding something for those 2 files in Depends.gnu*

[jayeshkrishna]

Are the changes BFB (BFB flag is missing in the PR desc, and the PR labels)?

[ndkeen]

I added a commit to the branch to change how we issue the -fallow-invalid-boz flag. Now it's only used for 2 specific files via Depends.gnu*. Re-tested e3sm_developer.

[ndkeen]

Closing this in favor of #4822