cmake HAVE_LIBDLPI examples

CTSRD-CHERI/cheribsd contrib/libpcap/CMakeLists.txt :2002 

check_function_exists(dlpi_walk HAVE_LIBDLPI)

asset-group/5ghoul-5g-nr-attacks libs/libpcap/CMakeLists.txt :1277 

check_function_exists(dlpi_walk HAVE_LIBDLPI)