Auto merge of #2058 - GuillaumeGomez:mac-adds, r=Amanieu
Auto merge of #2058 - GuillaumeGomez:mac-adds, r=Amanieu

Add getmntinfo and getmntinfo functions, MNT_WAIT and MNT_NOWAIT constants

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