8180415: Rebuild remembered sets during the concurrent cycle Summary: In general maintain remembered sets of old regions only from the start of the concurrent cycle to the mixed gc they are used, at most until the end of the mixed phase. Reviewed-by: sjohanss, sangheki

8197850: Calculate liveness in regions during marking Reviewed-by: sjohanss, sangheki

8197570: Make rules for choosing collection set candidates more explicit Reviewed-by: sangheki, sjohanss

8197569: Refactor eager reclaim for concurrent remembered set rebuilding Summary: Expose information about eager reclaim region selection. Reviewed-by: sjohanss, sangheki