Add statistical printout of rank_for_schedule decisions

Add statistical printout of rank_for_schedule decisions

	* haifa-sched.c (SCHED_SORT): Delete.  Macro used exactly once.
	(enum rfs_decition:RFS_*): New constants wrapped in an enum.
	(rfs_str): String corresponding to RFS_* constants.
	(rank_for_schedule_stats_t): New typedef.
	(rank_for_schedule_stats): New static variable.
	(rfs_result): New static function.
	(rank_for_schedule): Track statistics for deciding heuristics.
	(rank_for_schedule_stats_diff, print_rank_for_schedule_stats): New
	static functions.
	(ready_sort): Use them for debug printouts.
	(schedule_block): Init statistics state.  Print statistics on
	rank_for_schedule decisions.

From-SVN: r213709