Account for prologue spills in reg_pressure scheduling

Account for prologue spills in reg_pressure scheduling

	* haifa-sched.c (sched_class_regs_num, call_used_regs_num): New static
	arrays.  Use sched_class_regs_num instead of ira_class_hard_regs_num.
	(print_curr_reg_pressure, setup_insn_reg_pressure_info,)
	(model_update_pressure, model_spill_cost): Use sched_class_regs_num.
	(model_start_schedule): Update.
	(sched_pressure_start_bb): New static function.  Calculate
	sched_class_regs_num.
	(schedule_block): Use it.
	(alloc_global_sched_pressure_data): Calculate call_used_regs_num.

From-SVN: r216620