(S) RFR: 8157904: Atomic::cmpxchg for jbyte is missing a fence on initial failure

[Kim Barrett]

> On Aug 24, 2016, at 5:51 PM, David Holmes <david.holmes at oracle.com> wrote:
> 
> Thanks Volker!
> 
> Just waiting for Kim to give the all clear.

Sorry, I missed that you’d done an in-place update of the webrev.

I would have left align_ptr_down alone and cast away the volatile in cmpxchg,
but have no objection to the approach you’ve taken.

Looks good.