Suppressing occasional failures in copy2 regression test

Every so often the buildfarm shows row-ordering differences in the copy2
test, for example
http://www.pgbuildfarm.org/cgi-bin/show_log.pl?nm=jaguar&dt=2009-06-13%2003:00:02
("jaguar" seems particularly prone to this for some reason, but other
members have shown it too.)  I believe what is happening is that
autovacuum chances to trigger on the table being used, allowing some of
the updated rows to be placed in positions they're not normally placed
in.

There is a simple fix for that: change the table to be a temp table,
thus preventing autovac from touching it.

Any objections to doing that?
        regards, tom lane