Merge branch 'bldchn' into next

* bldchn:
  Summary: minor, tweak SXE_CHECK_LINKER_FLAGS Keywords: bldchn
  Summary: fix to fix, do not treat compiler flags as linker flags Keywords: bldchn
  Summary: minor, specifically check for all optimisation flags Keywords: bldchn
  Summary: fix, check for special diagnostic 10237 if CC=icc Keywords: bldchn
  Summary: fix, use all CFLAGS for linker flag check Keywords: bldchn
  Summary: minor, provide SXE_CHECK_COMPILER_XFLAG Keywords: bldchn