8034948: Back out JDK-6976350 since it does not fix any issue Summary: Revert JDK-6976350 because it does not improve PLAB fragmentation. To the contrary, it tends to increase the amount of wasted space with many threads. Reviewed-by: brutisso

8035329: Move G1ParCopyClosure::copy_to_survivor_space into G1ParScanThreadState Summary: Move G1ParCopyClosure::copy_to_survivor_space to decrease code size. Reviewed-by: stefank, jmasa

8035326: Assume non-NULL references in G1CollectedHeap::in_cset_fast_test Summary: Remove the assumption that G1CollectedHeap::in_cset_fast_test needs to check for NULL references. Most of the time this is not required, making the code doing this check multiple times. Reviewed-by: stefank, mgerdin, jmasa

8027559: Decrease code size and templatizing in G1ParCopyClosure::do_oop_work Summary: Move methods that are not dependent on any of G1ParCopyClosure's template parameters into G1ParCopyHelper. Further remove unused methods and members of the class hierarchy. Reviewed-by: mgerdin, stefank