* Add a cached_pages field to the system_info structure, and change the
meaning of the used_pages field to not include cached pages.
* Provide the needed info using the new calls vm_get_available_memory(),
and vm_page_num_available_pages().
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24571 a95241bf-73f2-0310-859d-f6bbb57e9c96