* wide-int.h (widest2_int): New.
	* gimple-fold.c (arith_overflowed_p): Use it.
	* tree.h (widest2_int_cst): New.
	* tree-vrp.c (wide_int_binop_overflow): Rename from
	vrp_int_const_binop.
	Rewrite to work on trees.
	(extract_range_from_multiplicative_op_1): Abstract code to...
	(wide_int_range_min_max): ...here.
	(wide_int_range_cross_product): ...and here.
	(extract_range_from_binary_expr_1): Abstract overflow code to...
	(wide_int_range_cross_product_wrapping): ...here.
	* tree-vrp.h (wide_int_range_cross_product): New.
	(wide_int_range_cross_product_wrapping): New.

From-SVN: r262874