[haifa-sched] model load/store multiples properly in autoprefetcher scheduling

[haifa-sched] model load/store multiples properly in autoprefetcher scheduling

	* sched-int.h (struct autopref_multipass_data_): Remove offset
	field.  Add min_offset, max_offset, multi_mem_insn_p fields.
	* haifa-sched.c (analyze_set_insn_for_autopref): New function.
	(autopref_multipass_init): Use it.  Handle PARALLEL sets.
	(autopref_rank_data): New function.
	(autopref_rank_for_schedule): Use it.
	(autopref_multipass_dfa_lookahead_guard_1): Likewise.

From-SVN: r228962