Reduce size of pointer_info tree, minor cleanups.

Reduce size of pointer_info tree, minor cleanups.

2012-01-29  Janne Blomqvist  <jb@gcc.gnu.org>

	* module.c (pointer_info): Make true_name and module pointers
	rather than arrays, order pointers before other fields.
	(free_pi_tree): free true_name and module as well.
	(mio_read_string): Rename to read_string.
	(mio_write_string): Remove.
	(load_commons): Use read_string.
	(read_module): Use read_string rather than mio_internal_string.
	(write_blank_common): Call write_atom directly.
	(write_symbol): Likewise.

From-SVN: r183681