cmake HAVE_PACKET_IS_LOOPBACK_ADAPTER examples

CTSRD-CHERI/cheribsd contrib/libpcap/CMakeLists.txt :598 

check_function_exists(PacketIsLoopbackAdapter HAVE_PACKET_IS_LOOPBACK_ADAPTER)

asset-group/5ghoul-5g-nr-attacks libs/libpcap/CMakeLists.txt :313 

check_function_exists(PacketIsLoopbackAdapter
                          HAVE_PACKET_IS_LOOPBACK_ADAPTER)