cmake HAS_ISNAN examples

NREL/EnergyPlus third_party/DElight/CMakeLists.txt :9 

TRY_COMPILE( HAS_ISNAN "${CMAKE_CURRENT_BINARY_DIR}" "${CMAKE_CURRENT_SOURCE_DIR}/has_isnan.c" )

NREL/EnergyPlus third_party/DElight/CMakeLists.txt :16 

ADD_DEFINITIONS(-DHAS_ISNAN)