Fortran: Fix gfc_maybe_dereference_var [PR104430][PR99585]

	PR fortran/99585
	PR fortran/104430

gcc/fortran/ChangeLog:

	* trans-expr.cc (conv_parent_component_references): Fix comment;
	simplify comparison.
	(gfc_maybe_dereference_var): Avoid d referencing a nonpointer.

gcc/testsuite/ChangeLog:

	* gfortran.dg/class_result_10.f90: New test.