Build system updates for Intel compilers

[mattw-nws]

Believed minimal set of changes to allow compilation with Intel (other?) compilers.

Additions

• Mainly added the ability to specify the compiler and build environment settings via environment variables
• Some capability to control compiler flags to Cython extension building pipelines
• A few void return types that weren't C-spec that the compilers complained about

Removals

• Explicit references to gcc, gfortran, libgfortran etc.

Changes

• Nothing functional

Testing

1. Tested with Intel OneAPI 2022.3.0 and also with GCC8 suite.
2. Integration test on NOAA-OWP/ngen
3. Test case added that can be used with ngen+t-route master branch in data/gauge_01073000 in ngen PR#502

Screenshots

Notes

Todos

Checklist

• PR has an informative and human-readable title
• Changes are limited to a single goal (no scope creep)
• Code can be automatically merged (no conflicts)
• Code follows project standards (link if applicable)
• Passes all existing automated tests
• Any change in functionality is tested
• New functions are documented (with a description, list of inputs, and expected output)
• Placeholder code is flagged / future todos are captured in comments
• Visually tested in supported browsers and devices (see checklist below 👇)
• Project documentation has been updated (including the "Unreleased" section of the CHANGELOG)
• Reviewers requested with the Reviewers tool ➡️

Testing checklist

Target Environment support

• Linux

[shorvath-noaa]

@mattw-nws When I try compiling this on apd-dev1 I get the following error:

(base) ./compiler.sh
using F90=gfortran
using CC=gcc
using NETCDFINC=/usr/include/openmpi-x86_64/
rm -f *.o *.mod
gfortran -g -c -O2 -fPIC -lgfortran -lgcc -static-gfortran -static-libgcc -no-defaultlibs varPrecision.f90
gfortran: error: unrecognized command line option ‘-static-gfortran’
gfortran: error: unrecognized command line option ‘-no-defaultlibs’
make: *** [precis.mod] Error 1

[mattw-nws]

@shorvath-noaa thanks... what's your gcc --version for that run? Admittedly I haven't tested in <GCC8. Though those flags were in the previous code... it may now be passing them to the linker or compiler where it was only passing to the other previously though.

[shorvath-noaa]

@mattw-nws

(base) gcc --version
gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-44)
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[mattw-nws]

🤦 @shorvath-noaa Missed commit in my GCC-environment working copy. Please pull and try again.

[shorvath-noaa]

Successfully compiled and ran LowerColorado_TX/test_AnA.yaml