These changes add Termio/Winsize/Statfs_t for AIX, constants TC[GS]ET and the syscalls Mkdir and Mknod.
It also changes the comments for AIX which still were talking about Linux and glibc.

Change-Id: I64325330328d6e16cff540f103fdfa533b7d8f5b
Reviewed-on: https://go-review.googlesource.com/136295
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>