Emacs should no longer hang at startup on kFreeBSD.

Emacs should no longer hang at startup on kFreeBSD.

Applied upstream patch (in conjunction with 5113963):

  Port close-on-exec pty creation to FreeBSD 9.1-RELEASE.

  * configure.ac (PTY_OPEN): If posix_openpt with O_CLOEXEC fails
  and reports EINVAL, try it again without O_CLOEXEC.  This should
  port PTY_OPEN to FreeBSD 9, which stupidly rejects O_CLOEXEC.
  What were they thinking?

Origin: upstream, commit: 5113964, 5c41cec3858f1828303b67be634b8c39937c8580
Added-by: Rob Browning <rlb@defaultvalue.org>
Provided-By: Paul Eggert  <eggert@cs.ucla.edu>
Bug: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=15129