Add REGISTRY for struct address_space.

Add REGISTRY for struct address_space.

This patch adds REGISTRY for struct address_space.

gdb:

2013-11-20  Yao Qi  <yao@codesourcery.com>

	* progspace.c (struct address_space): Update comments.
	<REGISTRY_FIELDS>: New fields.
	DEFINE_REGISTRY for address_space.
	(new_address_space): Call address_space_alloc_data.
	(free_address_space): Call address_space_free_data.
	* progspace.h: Use DECLARE_REGISTRY.