Added support for Cray Clang to Makefile.kokkos

[DavidPoliakoff]

Cray Clang doesn't identify with a "CC-" string, it says "clang++" and more. Mainline clang says

s1042027:kokkos dzpolia$ clang++ -craype-verbose
clang-9: error: unknown argument: '-craype-verbose'
clang-9: error: no input files

Note the lack of "clang++." I'm using this to switch what Cray flag we use, to better match the CMakeLists method, we want -fopenmp as the flag for OpenMP for Cray Clang, not -fopenmp=libomp

[masterleinad]

Looks reasonable to me.

[Rombur]

This works but note that if you ask for the version, clang gives you something like clang version 10.0.0-4ubuntu1 while Cray clang gives you Cray clang version 12.0.2. It might be more robust in the long term to check the version. Since it's a Makefile, the current solution is good enough for me.

[dalg24]

This works but note that if you ask for the version, clang gives you something like clang version 10.0.0-4ubuntu1 while Cray clang gives you Cray clang version 12.0.2. It might be more robust in the long term to check the version. Since it's a Makefile, the current solution is good enough for me.

@DavidPoliakoff do you want me to merge as is or do you want to update according to Brunos suggestion?

[DavidPoliakoff]

Hold off on merging this, I'll check it out on a machine. I'd like for the string we grep for to be Cray, I just need to verify