Auto merge of #1024 - nielx:master, r=alexcrichton
Auto merge of #1024 - nielx:master, r=alexcrichton

Haiku: Add more IP_* and IPV6_* constants.

These are used in the socket2 library.

rust-lang-nursery/libc,rust-lang/libc,rust-lang/libc,rust-lang-nursery/libc,rust-lang-nursery/libc,rust-lang/libc