search.c (dfs_canonical_queue): New function.

	* search.c (dfs_canonical_queue): New function.
	(dfs_assert_unmarked_p): Likewise.
	(assert_canonical_unmarked): Likewise.
	(access_in_type): Use it.
	(accessible_p): Likewise.  Walk the whole tree when umarking.

From-SVN: r25668