checked does not handle the -x operation.

[nan01ab]

In inc operation, Neo-VM script and standard C# program will throw an Exception both if src overflowed:

public static int Inc(int src)
{
     return checked(++src);
}

In -x operation, standard C# program will throw an Exception if src overflowed(src is -2147483648), but Neo-VM script not:

public static int Negative(int src)
{
     return checked(-src);
}

[Jim8y]

This apparently a compiler bug, please fix it.

[Hecate2]

Better to merge #1205 first