8132306: java/lang/ref/ReferenceEnqueue.java fails with "RuntimeException: Error: poll() returned null; expected ref object" Summary: Carefully order ref.queue and queue list updates to address races. Reviewed-by: dholmes, dfuchs, plevart

^build/
^dist/
^webrev
^.idea
/nbproject/private/
^.hgtip
.DS_Store