cmake HAVE_SIO_OPEN examples

LMMS/lmms cmake/modules/FindSndio.cmake :22 

check_library_exists(sndio sio_open "${SNDIO_LIBRARY_DIR}" HAVE_SIO_OPEN)

LMMS/lmms cmake/modules/FindSndio.cmake :27 

find_package_handle_standard_args(Sndio DEFAULT_MSG SNDIO_LIBRARY SNDIO_INCLUDE_DIR HAVE_SIO_OPEN)