message: Updated clang@coral_xlf compilers on blues_os.
  Rich suggested that the 10.13 drop of the clang/xl compilers are
  currently the most stable.
diff: @@ -94,10 +94,10 @@ compilers:
  fc: /usr/tce/packages/intel/intel-18.0.0/bin/ifort
  blueos_3_ppc64le_ib:
  clang@coral_xlf:
  - cc: /usr/tce/packages/xl/xl-beta-2017.11.28/bin/xlc
  - cxx: /usr/tce/packages/xl/xl-beta-2017.11.28/bin/xlc++
  - f77: /usr/tce/packages/xl/xl-beta-2017.11.28/bin/xlf90
  - fc: /usr/tce/packages/xl/xl-beta-2017.11.28/bin/xlf90
  + cc: /usr/tce/packages/clang/clang-coral-2017.10.13/bin/clang
  + cxx: /usr/tce/packages/clang/clang-coral-2017.10.13/bin/clang++
  + f77: /usr/tce/packages/xl/xl-beta-2017.10.13/bin/xlf
  + fc: /usr/tce/packages/xl/xl-beta-2017.10.13/bin/xlf2003
  clang@coral_xlflang:
  cc: /usr/tce/packages/clang/clang-coral-2017.11.27/bin/clang
  cxx: /usr/tce/packages/clang/clang-coral-2017.11.27/bin/clang++
  