re PR fortran/60956 (error reading (and writing) large text files in gfortran)

re PR fortran/60956 (error reading (and writing) large text files in gfortran)

2015-03-22  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

	PR libgfortran/60956
	Backport from mainline
	* io/fbuf.c (fbuf_flush_list): New function that only flushes
	if current fbuf position exceeds a limit.
	* io/fbuf.h: Declare the new function.
	* io/io.h (enum unit_mode): Add two new modes.
	* io/list_read.c (list_formatted_read_scalar): Call new function.
	* io/write.c: Include fbuf.h. (list_formatted_write_scalar):
	Call new function.

From-SVN: r221578