PR debug/21828
	* toplev.c (check_global_declarations): Do not mark undefined
	variables as DECL_IGNORED_P.
	* varasm.c (first_global_object_name): GTY it.
	(weak_global_object_name): Likewise.
	(notice_global_symbol): Use ggc_strdup, not xstrdup, when creating
	a string to go into {weak,first}_global_object_name.

	PR debug/21828
	* gcc.dg/debug/dwarf2/dwarf-uninit.c: New test.

From-SVN: r102287