2016-10-31  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

	PR fortran/54679
	* io.c (check_format): Adjust checks for FMT_L to treat a zero
	width as an extension, giving warnings or error as appropriate.
	Improve messages.
	PR libgfortran/54679
	* io/format.c (parse_format_list): Adjust checks for FMT_L to
	treat a zero width as an extension, giving warnings or error
	as appropriate. Improve messages.
	PR fortran/54679
	* gfortran.dg/fmt_l.f90: Update test.
	* gfortran.dg/fmt_l0.f90: New test.

From-SVN: r241720