RFR for JDK-8031374: java/util/concurrent/ConcurrentQueues/OfferRemoveLoops.java fails Intermittently

[Martin Buchholz]

Thanks, David - I didn't know about CFS - Completely Fair Scheduler - and
yield, but:

It seems it's mostly about a thread not starving a lower-priority process.
 This is only a test, and yield is only here to help the other thread at
the same priority gets some cycles, so it should be Mostly Harmless.  That
said, I eliminated one set of yields.