Compiler workaround: Pull internal subroutine out to module-level

[billsacks]

This shouldn't be needed, but is needed with some Mac configurations to work around an issue with clang.

Resolves #8

@theurich - any objections to this change?

[billsacks]

I have tested this on green and hearhear and it resolves the failure in ExternalDriverAPIWeakCplDAProto on both.

[theurich]

Feels like bending over backward to make Darwin happy.... not the first time, and also probably not the last time. Just happy you found a reasonable workaround!

[billsacks]

Feels like bending over backward to make Darwin happy.... not the first time, and also probably not the last time.

Totally agreed.

(And now I'm working on another issue on hearhear that I think is due to the lack of openmp support in Apple's clang, since

nuopc-app-prototypes/testProtos.sh

Lines 24 to 33 in f3bc6c1

	if [[ $OSTYPE = *darwin* ]]
	then
	# Darwin systems that use Apple Clang need extra environment variables
	# to find the libomp installation. These are important for the ESMX
	# tests where CMake is used under the hood to determine the correct
	# compiler and linker flags. Set them here to be available:
	export LDFLAGS=-L/opt/homebrew/opt/libomp/lib
	export CXXFLAGS=-I/opt/homebrew/opt/libomp/include
	export CFLAGS=-I/opt/homebrew/opt/libomp/include
	fi

doesn't work in this spack-based setup.... Ah, Apple, why do you make things so difficult?)

[billsacks]

@theurich FYI, since I know how much you like these Darwin workarounds, here's the other fix I'm needing with the spack-based setup:

https://github.com/esmf-org/nuopc-app-prototypes/compare/dfda6215632e2be20f231510c1560bd453c3291a..dc43e0f417661766c6ec4bc36662d39c892f0269