RFR: 8146989: Introduce per-worker preserved mark stacks in ParNew

[Thomas Schatzl]

Hi Tony,

On Fri, 2016-02-05 at 09:18 -0500, Tony Printezis wrote:
> Updated webrev with a small change suggested by John Coomes (CCed) to
> move the in_c_heap arg to the c’tor instead of the init() / reclaim()
> methods:
> 
> http://cr.openjdk.java.net/~tonyp/8146989/webrev.3/
> 

  overall looks good, although I will take another look. Let me run a
few tests with it.

Thanks,
  Thomas