Add SO_TIMESTAMP for OpenBSD like OSes
Add SO_TIMESTAMP for OpenBSD like OSes

rust-lang/libc,mneumann/libc,rust-lang-nursery/libc,mneumann/libc,rust-lang-nursery/libc,cactorium/libc,rust-lang/libc,rust-lang/libc,mneumann/libc,rust-lang-nursery/libc,cactorium/libc,cactorium/libc