RFR 8006007: j.u.c.atomic classes should use intrinsic getAndXXX provided by 7023898

[Chris Hegarty]

Doug, Aleksey,

I updated the appropriate methods in the Atomic classes to use the 
instinsics defined by 7023898 , Unsafe getAndAddInt, getAndSetInt, 
getAndAddLong, getAndSetLong, getAndSetObject.

http://cr.openjdk.java.net/~chegar/8006007/webrev.00/webrev/

This patch also includes some trivial cleanup and consistent style CAS 
loop from Dougs CVS, but excludes the new lambda versions of 
get/updateAndUpdate/Get and get/accumulateAndAccumulate/Get. These new 
methods are not impacted by the intrinsis. I will immediately follow 
these changes with a request to add these new methods, I just don't want 
to tie this update to a spec change request.

Doug,
  If you are agree I will create a patch containing these changes, based 
on the sources in your CVS.

-Chris.