Unbricked Link impl doesn't use the tail call optimisation

[quinnyo]

The Link code has a few functions that end with a call asdf immediately followed by a ret. This uses can be replaced with a single jp asdf which uses less cycles and is less lines of code.

[avivace]

@quinnyo would you like to work on this? Maybe introducing the optimisation the first time "explicitly"? (spelling it out?)

[quinnyo]

I don't think the code with this change would be a problem for anyone at that point in the tutorial. The behaviour of the instructions should at least make sense, even without the awareness of the optimisation.

But I agree that it's worth including an explanation, I'm just worried that it will get a bit lost in the serial lesson.

a short explanation might be something along the lines of:

This routine ends by jumping (jp) directly to another one in order to avoid the overhead of a tail call, which is when a normal call is performed only to unconditionally ret immediately after the subroutine returns.