If the StreamReadConstraints are set to Integer.MAX_VALUE, reading a string results in an infinite loop due to the value of max overflowing to a negative value. while (ptr < max) is always false so break ascii_loop is never reached.

This change uses Math.addExact to throw an ArthimeticException if an overflow were to occur and sets max to max integer, allowing the loop to break and large strings to be properly deserialized.