Re: integer overflow in muli instruction

[Jose E. Marchesi]

>> But then, at this point we have to decide what semantics to implement in
>> Poke when signed overflow happens (in multiplication, division, etc).
>> 
>> Adopting C semantics, and raising a Poke exception seems to be the most
>> obvious choice...
>
> Yes, this seems the right thing to do. The programmer can then decide
> whether they want to use a 64-bit type or an unsigned type as a workaround.

All right, poke now checks for overflows in:

- Signed addition.
- Signed subtraction.
- Signed multiplication.
- Signed division.
- Signed ceil division.
- Signed remainder.
- Signed Negation.

At both run-time (exception E_overflow) and compile-time (constant
folding).