hg: jdk/sandbox: 8206467: Refactor G1ParallelCleaningTask into shared

[chris.hegarty at oracle.com]

Changeset: 6c0ac4b4d761
Author:    zgu
Date:      2018-08-21 20:29 -0400
URL:       http://hg.openjdk.java.net/jdk/sandbox/rev/6c0ac4b4d761

8206467: Refactor G1ParallelCleaningTask into shared
Summary: Refactored and moved G1ParllelCleaningTask to be shared among GCs
Reviewed-by: rkennke, kbarrett

! src/hotspot/share/gc/g1/g1CollectedHeap.cpp
+ src/hotspot/share/gc/shared/parallelCleaning.cpp
+ src/hotspot/share/gc/shared/parallelCleaning.hpp