Feature: carry flag for subtract in ALU

[jxors]

Is your feature request related to a problem? Please describe

Is there a reason the ALU always sets the carry to zero for subtraction?

To me it would make more sense if a subtraction A-B behaved as an addition A+(-B). This would make the ALU more similar to how, for example, x86 and ARM behave.

Describe the solution you'd like

Change the ALU such that subtraction outputs a carry.

I'm happy to implement this if you're willing to accept such a change.

Describe alternatives you've considered

No response

Additional context

No response

Are you working on this?

Yes