Call for perf testers.

I announced a patch on arch_at_ that allows us to reclaim vnode memory as
well as more intelligently cache files which are only stat'd and not read.
See the arch post for details.

I'd like it if people could run with the patch to test for bugs, but I'd
also like it if a few people could time buildworlds with and without the
patch.  It is available at:

http://www.chesapeake.net/~jroberson/freevnodes.diff

Cheers,
Jeff