RFR (M): 8035330: Remove G1ParScanPartialArrayClosure and G1ParScanHeapEvacClosure

[Thomas Schatzl]

Hi all,

  can I have reviews for the following change that changes the
G1ParScanPartialArrayClosure and G1ParScanHeapEvacClosure closures into
methods of G1ParScanThreadState?

G1ParScanPartialArrayClosure and G1ParScanHeapEvacClosure are two
closures which do_oop_nv method is always called directly and from a
single location, i.e. G1ParScanThreadState.

This change removes the boiler plate code of these "closures" to avoid
more confusion (G1ParScanHeapEvacClosure was a candidate for oop closure
specialization although it was never called on an oop_iterate() method),
makes the do_oop_nv() methods into two methods of G1ParScanThreadState,
in addition to moving related code also into the vicinity.

Another minor change is that do_oop_evac() (the replacement for
G1ParScanHeapEvacClosure::do_oop_nc()) is stripped of the not-required
NULL check.

CR:
https://bugs.openjdk.java.net/browse/JDK-8035330

Webrev:
http://cr.openjdk.java.net/~tschatzl/8035330/webrev/

Based on the changes for 8035326 recently posted here.

Testing:
jprt

Thanks,
  Thomas