Unify MULT_EXPR range operator

Move the declaration of the class to the range-op-mixed header, add the
floating point prototypes as well, and use it in the new unified table.

	* range-op-float.cc (foperator_mult_div_base): Delete.
	(foperator_mult_div_base::find_range): Make static local function.
	(foperator_mult): Remove.  Move prototypes to range-op-mixed.h
	(operator_mult::op1_range): Rename from foperator_mult.
	(operator_mult::op2_range): Ditto.
	(operator_mult::rv_fold): Ditto.
	(float_table::float_table): Remove MULT_EXPR.
	(class foperator_div): Inherit from range_operator.
	(float_table::float_table): Delete.
	* range-op-mixed.h (class operator_mult): Combined from integer
	and float files.
	* range-op.cc (float_tree_table): Delete.
	(op_mult): New object.
	(unified_table::unified_table): Add MULT_EXPR.
	(get_op_handler): Do not check float table any longer.
	(class cross_product_operator): Move to range-op-mixed.h.
	(class operator_mult): Move to range-op-mixed.h.
	(integral_table::integral_table): Remove MULT_EXPR.
	(pointer_table::pointer_table): Remove MULT_EXPR.
	* range-op.h (float_table): Remove.