previous commit affected rather many test, as the implicit returns add extra instructions
Also added some explicit returns, so as not to test the return logic too much. return (ie return nl) is a knonwn 3 risc operation.
Since Builtin generates risc, just like mom instructions, it was a design mistake to put builtin into risc in the first place. Now that borders are coming more into focus, it make much more sense to have the builtin in mom.
In fact the instructions should be moved out and a seperate invocation mechanism used , so functions can be parsed, not generated (wip)
