so many relied (implicitly( on some builtin function
after all can't do much in ruby without calling
Now all those dependencies are explicit
Small risc changes come because the macro version has a return label and unreachable label
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.
