Auto merge of #485 - dhduvall:solaris-flock, r=alexcrichton
Auto merge of #485 - dhduvall:solaris-flock, r=alexcrichton

Add Solaris constants for fcntl-style advisory locking

Solaris doesn't implement flock(), so any Rust implementation of flock()
will need to implement it using fcntl(), using the F_RDLCK, F_WRLCK, and
F_UNLCK constants.

rust-lang/libc,mneumann/libc,anatol/libc,anatol/libc,philippkeller/libc,anatol/libc,cactorium/libc,philippkeller/libc,rust-lang/libc,rust-lang/libc,cactorium/libc,superriva/libc,rust-lang-nursery/libc,mneumann/libc,superriva/libc,rust-lang-nursery/libc,mneumann/libc,philippkeller/libc,superriva/libc,rust-lang-nursery/libc,cactorium/libc