RFR (S): 8150630: Add logging for ParScanThreadState merge phase

[Thomas Schatzl]

Hi Jon,

On Thu, 2016-02-25 at 07:09 -0800, Jon Masamitsu wrote:
> http://cr.openjdk.java.net/~tschatzl/8150630/webrev/src/share/vm/gc/g
> 1/g1GCPhaseTimes.cpp.frames.html
> 
> 416 print_stats(Indents[2], "Merge PSS",
> _recorded_merge_pss_time_ms);
> 
> I would appreciate a label easier for me to understand such as
> 
> "Merge parallel threads data"
> 
> or
> 
> "Merge parallel threads data (PSS)"
> 
> Otherwise, looks good.
> 

  thanks for the review. Would "Merge per-thread state" be okay with
you?

Thanks,
  Thomas