Enabled via REL2_1.
Added support for doing object collapses "on the fly". Enabled via REL2_1a.
Improved object collapses so that they can happen in more cases. Improved
sensing of modified pages to fix an apparant race condition and improve
clustered pageout opportunities. Fixed an "oops" with not restarting page
scan after a potential block in vm_pageout_clean() (not doing this can result
in strange behavior in some cases).
Submitted by: John Dyson & David Greenman
