8138752: G1CollectorPolicy::should_should_update_surv_rate_group_predictors() uses wrong predicate Summary: Instead of only updating the survivor rate groups in the young gc after marking and before mixed gc, update them during young gcs outside of marking Reviewed-by: mgerdin, drwhite

8138750: Remove dead code in survivor rate group Reviewed-by: mgerdin, tbenson

8139583: Fix formatting in survRateGroup.cpp Reviewed-by: kbarrett, stefank

8137082: Factor out G1 prediction code from G1CollectorPolicy and clean up Summary: Factor out G1 prediction code from G1CollectorPolicy into its own class, constify methods of G1CollectorPolicy and move more implementations to the cpp file. Reviewed-by: jmasa, sangheki, ecaspole, kbarrett