* recog.c (peep2_do_rebuild_jump_labels, peep2_do_cleanup_cfg): New
	static variables.
	(peep2_buf_position): New static function.
	(peep2_regno_dead_p, peep2_reg_dead_p, peep2_find_free_register,
	peephole2_optimize): Use it.
	(peep2_attempt, peep2_update_life): New static functions, broken out
	of peephole2_optimize.
	(peep2_fill_buffer): New static function.
	(peephole2_optimize): Change the main loop to try to fill the buffer
	with the maximum number of insns before matching them against
	peepholes.  Use a forward scan.  Remove special case for targets with
	conditional execution.
	* genrecog.c (change_state): Delete dead code.
	* config/i386/i386.md (peephole2 for arithmetic ops with memory):
	Rewrite so as not to expect the second insn to have had a peephole
	applied yet.

From-SVN: r161570