re PR rtl-optimization/56117 (ICE: in cselib_subst_to_values, at cselib.c:1853...

re PR rtl-optimization/56117 (ICE: in cselib_subst_to_values, at cselib.c:1853 with -O2 -fsched2-use-superblocks and __builtin_prefetch())

	PR rtl-optimization/56117
	* sched-deps.c (sched_analyze_2) <case PREFETCH>: For use_cselib
	call cselib_lookup_from_insn on the MEM before calling
	add_insn_mem_dependence.

	* gcc.dg/pr56117.c: New test.

From-SVN: r195513