* sched-int.h (schedule_block): Adjust declaration.
* sched-rgn.c (bb_state_array, bb_state): New static variables.
(sched_rgn_init): Initialize them.
(sched_rgn_free): Free them.
(schedule_region): Save scheduling state for future blocks, and
pass such state to schedule_block.
* params.def (PARAM_SCHED_STATE_EDGE_PROB_CUTOFF): New.
* doc/invoke.texi (--param): Document it.
* haifa-sched.c (schedule_block): New arg init_state. Use it to
initialize state if nonnull. All callers changed.
Call advance_one_cycle after scheduling.