cmake HAVE_EPOLL_CLOEXEC examples

zeromq/libzmq CMakeLists.txt :410

check_cxx_symbol_exists(epoll_create1 sys/epoll.h HAVE_EPOLL_CLOEXEC)

asset-group/5ghoul-5g-nr-attacks libs/libzmq/CMakeLists.txt :376

check_cxx_symbol_exists(epoll_create1 sys/epoll.h HAVE_EPOLL_CLOEXEC)