vm_page_write_modified_pages(), save that it only writes pages in the
given range.
* Added vm_page_schedule_write_page_range() which schedules all modified
pages in the given cache's range for writing by the page writer.
* Added _kern_sync_memory() syscall and the msync() POSIX function.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25620 a95241bf-73f2-0310-859d-f6bbb57e9c96