message: allow space separated list of flags for ISPC commands, just like CXX flags
diff: @@ -110,11 +110,11 @@ MACRO (OSPRAY_ISPC_COMPILE)
  ENDIF()
  #CAUTION: -O0/1 -g with ispc seg faults
  - SET(ISPC_FLAGS_DEBUG -g CACHE STRING "ISPC Debug flags")
  + SET(ISPC_FLAGS_DEBUG "-g" CACHE STRING "ISPC Debug flags")
  MARK_AS_ADVANCED(ISPC_FLAGS_DEBUG)
  - SET(ISPC_FLAGS_RELEASE -O3 CACHE STRING "ISPC Release flags")
  + SET(ISPC_FLAGS_RELEASE "-O3" CACHE STRING "ISPC Release flags")
  MARK_AS_ADVANCED(ISPC_FLAGS_RELEASE)
  - SET(ISPC_FLAGS_RELWITHDEBINFO -O2 -g CACHE STRING "ISPC Release with Debug symbols flags")
  + SET(ISPC_FLAGS_RELWITHDEBINFO "-O2 -g" CACHE STRING "ISPC Release with Debug symbols flags")
  MARK_AS_ADVANCED(ISPC_FLAGS_RELWITHDEBINFO)
  IF (WIN32 OR "${CMAKE_BUILD_TYPE}" STREQUAL "Release")
  SET(ISPC_OPT_FLAGS ${ISPC_FLAGS_RELEASE})
  @@ -124,6 +124,9 @@ MACRO (OSPRAY_ISPC_COMPILE)
  SET(ISPC_OPT_FLAGS ${ISPC_FLAGS_RELWITHDEBINFO})
  ENDIF()
  + # turn space sparated list into ';' separated list
  + STRING(REPLACE " " ";" ISPC_OPT_FLAGS "${ISPC_OPT_FLAGS}")
  +
  IF (NOT WIN32)
  SET(ISPC_ADDITIONAL_ARGS ${ISPC_ADDITIONAL_ARGS} --pic)
  ENDIF()
  