re PR debug/41558 (gfortran -O code excessive DW_OP_deref's)

re PR debug/41558 (gfortran -O code excessive DW_OP_deref's)

	PR debug/41558
	* dwarf2out.c (loc_by_reference): Removed.
	(dw_loc_list_1): New function.
	(dw_loc_list): Remove toplev argument, add want_address argument.
	Don't look at decl_by_reference_p at all.  Use dw_loc_list_1.
	(loc_list_from_tree) <case VAR_DECL>: Pass want_address rather than
	want_address == 2 to dw_loc_list.  For successful dw_loc_list
	set have_address to 1 only if want_address is not 0.

	* gcc.dg/guality/guality.exp: Move gdb-test proc into...
	* lib/gcc-gdb-test.exp: ... here.  New file.
	* gfortran.dg/guality/guality.exp: New file.
	* gfortran.dg/guality/pr41558.f90: New test.
	* gfortran.dg/guality/arg1.f90: New test.

From-SVN: r152467