PR fortran/50981

	PR fortran/50981
	* trans-array.h (gfc_walk_elemental_function_args): New argument.
	* trans-intrinsic.c (gfc_walk_intrinsic_function): Update call.
	* trans-stmt.c (gfc_trans_call): Ditto.
	* trans-array.c (gfc_walk_function_expr): Ditto.
	(gfc_walk_elemental_function_args): Get the dummy argument list
	if possible.  Check that the dummy and the actual argument are both
	optional, and set can_be_null_ref accordingly.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@182875 138bc75d-0d04-0410-961f-82ee72b054a4