re PR libfortran/77868 (Fail to NULL guard check for internal unit in inquire_via_unit)

2016-10-05  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

	PR fortran/77868
	* io/inquire.c (inquire_via_unit): NULL guard the check for
	internal unit passed into child IO procedure.

	* gfortran.dg/dtio_15.f90: Fix spaces in dg-do.
	* gfortran.dg/class_array_20.f03: Likewise.
	* gfortran.dg/class_array_21.f03: Likewise.
	* gfortran.dg/finalize_29.f08: Likewise.
	* gfortran.dg/unlimited_polymorphic_23.f90: Likewise.

From-SVN: r240794