PR 50016 Slow I/O on MingW due to _commit

PR 50016 Slow I/O on MingW due to _commit

frontend ChangeLog:

2011-11-09  Janne Blomqvist  <jb@gcc.gnu.org>

	PR libfortran/50016
	* gfortran.texi (Data consistency and durability): New section.

testsuite ChangeLog:

2011-11-09  Janne Blomqvist  <jb@gcc.gnu.org>

	PR libfortran/50016
	* gfortran.dg/inquire_size.f90: Don't flush the unit.

libgfortran ChangeLog:

2011-11-09  Janne Blomqvist  <jb@gcc.gnu.org>

	PR libfortran/50016
	* io/inquire.c (inquire_via_unit): Flush the unit and use ssize.
	* io/unix.c (buf_flush): Don't call _commit.

From-SVN: r181207