Add overflow API for plus minus mult on range

Add overflow API for plus minus mult on range

In previous reviews, adding overflow APIs to range-op would be useful.
Those APIs could help to check if overflow happens when operating
between two 'range's, like: plus, minus, and mult.

Previous discussions are here:
https://gcc.gnu.org/pipermail/gcc-patches/2023-July/624067.html
https://gcc.gnu.org/pipermail/gcc-patches/2023-July/624701.html

gcc/ChangeLog:

	* range-op-mixed.h (operator_plus::overflow_free_p): New declare.
	(operator_minus::overflow_free_p): New declare.
	(operator_mult::overflow_free_p): New declare.
	* range-op.cc (range_op_handler::overflow_free_p): New function.
	(range_operator::overflow_free_p): New default function.
	(operator_plus::overflow_free_p): New function.
	(operator_minus::overflow_free_p): New function.
	(operator_mult::overflow_free_p): New function.
	* range-op.h (range_op_handler::overflow_free_p): New declare.
	(range_operator::overflow_free_p): New declare.
	* value-range.cc (irange::nonnegative_p): New function.
	(irange::nonpositive_p): New function.
	* value-range.h (irange::nonnegative_p): New declare.
	(irange::nonpositive_p): New declare.