2016-10-07  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/77406
	* interface.c (gfc_compare_interfaces): Fix detection of ambiguous
	interface involving alternate return.
	(check_interface1): Improve error message and loci.

2016-10-07  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/77406
	* gfortran.dg/pr77406.f90: New test.
	* gfortran.dg/assumed_type_3.f90: Update error messages.
	* gfortran.dg/defined_operators_1.f90: Ditto.
	* gfortran.dg/generic_26.f90: Ditto.
	* gfortran.dg/generic_7.f90: Ditto.
	* gfortran.dg/gomp/udr5.f90: Ditto.
	* gfortran.dg/gomp/udr7.f90: Ditto.
	* gfortran.dg/interface_1.f90: Ditto.
	* gfortran.dg/interface_37.f90: Ditto.
	* gfortran.dg/interface_5.f90: Ditto.
	* gfortran.dg/interface_6.f90: Ditto.
	* gfortran.dg/interface_7.f90
	* gfortran.dg/no_arg_check_3.f90
	* gfortran.dg/operator_5.f90
	* gfortran.dg/proc_ptr_comp_20.f90: Ditto.

From-SVN: r240870