cmake _HAVE_CLOCK_GETTIME_2 examples

asset-group/5ghoul-5g-nr-attacks libs/react-cpp/libev/CMakeLists.txt :80 

check_symbol_exists(clock_gettime time.h _HAVE_CLOCK_GETTIME_2)

asset-group/5ghoul-5g-nr-attacks libs/react-cpp/libev/CMakeLists.txt :85 

unset(_HAVE_CLOCK_GETTIME_2)