cmake _HAVE_NANOSLEEP_2 examples

asset-group/5ghoul-5g-nr-attacks libs/react-cpp/libev/CMakeLists.txt :93 

check_symbol_exists(nanosleep time.h _HAVE_NANOSLEEP_2)

asset-group/5ghoul-5g-nr-attacks libs/react-cpp/libev/CMakeLists.txt :98 

unset(_HAVE_NANOSLEEP_2)