<netinet/in.h>: add missing declaration of in_port_t and in_addr_t.
<netinet/in.h>: add missing declaration of in_port_t and in_addr_t.

lwip just uses u16_t/u32_t directly (see <ipv4/lwip/inet.h>).

8l/barrelfish,8l/barrelfish,mslovy/barrelfish,mslovy/barrelfish,utsav2601/cmpe295A,BarrelfishOS/barrelfish,linusyang/barrelfish,BarrelfishOS/barrelfish,utsav2601/cmpe295A,BarrelfishOS/barrelfish,linusyang/barrelfish,linusyang/barrelfish,mslovy/barrelfish,kishoredbn/barrelfish,8l/barrelfish,kishoredbn/barrelfish,kishoredbn/barrelfish,utsav2601/cmpe295A,8l/barrelfish,utsav2601/cmpe295A,mslovy/barrelfish,linusyang/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,mslovy/barrelfish,kishoredbn/barrelfish,mslovy/barrelfish,utsav2601/cmpe295A,utsav2601/cmpe295A,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,8l/barrelfish,8l/barrelfish,linusyang/barrelfish