6666739: (ref) ReferenceQueue.poll() doesn't scale well 6711667: (ref) Update SoftReference timestamp only if clock advances
This is forward-port from 6u14 of two scalability fixes. These were original fixed by Tom Rodriguez in an earlier update.
The webrev is here: http://cr.openjdk.java.net/~alanb/6666739%2b6711667/webrev.00/ Thanks, Alan.
