io.c: sync from upstream r1.24

"Sun Aug 10 02:44:26 2014 UTC
Replace F_DUPFD followed by setting FD_CLOEXEC with just
F_DUPFD_CLOEXEC

ok matthew@ millert@"

/guenther@/
tty.c: sync from upstream r1.10

"Sun Aug 10 02:44:26 2014 UTC
Replace F_DUPFD followed by setting FD_CLOEXEC with just
F_DUPFD_CLOEXEC

ok matthew@ millert@"

/guenther@/