Auto merge of #1189 - pusateri:recvdstaddr, r=alexcrichton

Add IP_RECVDSTADDR on netbsd.

Accidentally left out IP_RECVDSTADDR on NetBSD in #1184

Author: bors

src/unix/bsd/netbsdlike/netbsd/mod.rs

@@ -393,6 +393,8 @@ pub const F_GETNOSIGPIPE: ::c_int = 13;
 pub const F_SETNOSIGPIPE: ::c_int = 14;
 pub const F_MAXFD: ::c_int = 11;
 
+pub const IP_RECVDSTADDR: ::c_int = 7;
+pub const IP_SENDSRCADDR: ::c_int = IP_RECVDSTADDR;
 pub const IP_RECVIF: ::c_int = 20;
 pub const IP_PKTINFO: ::c_int = 25;
 pub const IP_RECVPKTINFO: ::c_int = 26;