message: Bump required ISPC version to 1.9.1 (for SKX target)
diff: ## ======================================================================== ##
  # ISPC versions to look for, in decending order (newest first)
  -SET(ISPC_VERSION_WORKING "1.9.1" "1.9.0")
  +SET(ISPC_VERSION_WORKING "1.9.1")
  LIST(GET ISPC_VERSION_WORKING -1 ISPC_VERSION_REQUIRED)
  IF (NOT ISPC_EXECUTABLE)
  @@ -155,12 +155,7 @@ MACRO (OSPRAY_ISPC_COMPILE)
  LIST(APPEND ISPC_TARGETS sse2)
  ENDIF()
  FOREACH(target ${ISPC_TARGETS})
  - # in v1.9.0 ISPC changed the ISA suffix of avx512knl-i32x16 to just 'avx512knl'
  - IF (${target} STREQUAL "avx512knl-i32x16" AND NOT ISPC_VERSION VERSION_LESS "1.9.0")
  - SET(target "avx512knl")
  - ELSEIF (${target} STREQUAL "avx512skx-i32x16")
  - SET(target "avx512skx")
  - ENDIF()
  + STRING(REPLACE "-i32x16" "" target ${target}) # strip avx512(knl|skx)-i32x16
  SET(results ${results} "${outdir}/${fname}.dev_${target}${ISPC_TARGET_EXT}")
  ENDFOREACH()
  