* parse.y (named_complex_class_head_sans_basetype):
	Do nothing for error_mark_node.
	(maybe_base_class_list): Likewise.
	* decl.c (start_decl): Check for error_mark_node as a type.
	Detected by g++.brendan/array-refs.C.
	(start_decl_1): Likewise. Detected by g++.bugs/900322_01.C.
	(maybe_build_cleanup_1): Likewise. Detected by
	g++.jason/incomplete1.C.
	* tree.c (build_dummy_object): Use void_zero_node instead of the
	error_mark_node
	(is_dummy_object): Check for such a node.  Detected by
	g++.bob/inherit1.C

From-SVN: r25812