* rtl.h: Include hashtab.h.
	(iterative_hash_rtx): New prototype.
	* rtl.c (iterative_hash_rtx): New function.
	* dwarf2out.c (dw_loc_list_node): Add hash and emitted fields.
	(output_loc_list): Return immediately if emitted is set,
	set it.
	(hash_loc_operands, hash_locs, hash_loc_list,
	compare_loc_operands, compare_locs, loc_list_hash, loc_list_eq,
	optimize_location_lists_1, optimize_location_lists): New function.
	(dwarf2out_finish): Call optimize_location_lists.
	* Makefile.in (RTL_BASE_H): Depend on $(HASHTAB_H).

From-SVN: r165351