8049051: Use of during_initial_mark_pause() in G1CollectorPolicy::record_collection_pause_end() prevents use of seperate object copy time prediction during marking Summary: Replaced use of during_initial_mark_pause() with the variable last_pause_included_initial_mark that holds the real old value of _during_initial_mark_pause. Reviewed-by: brutisso, ehelin

project=jdk8
bugids=dup