bug#12800: Assume at least POSIX.1-1988 for getpgrp, setpgid, setsid.

[Eli Zaretskii]

> Date: Sun, 04 Nov 2012 11:25:55 -0800
> From: Paul Eggert <eggert@cs.ucla.edu>
> 
> @@ -2918,36 +2914,9 @@
>  static void
>  dissociate_if_controlling_tty (int fd)
>  {
> -#ifndef DOS_NT
>    pid_t pgid = tcgetpgrp (fd); /* If tcgetpgrp succeeds, fd is the ctty. */

The removal of the #ifndef will need a tcgetpgrp emulation for DOS_NT
platforms, I think.

Otherwise, I see no problems with this.

Thanks.