CardinalString reverse

.sub 'reverse' :method
    .local pmc res
    .local int i

    res = new 'CardinalString'

    .local pmc iterator, item
    iterator = iter self
  each_loop:
    unless iterator goto each_loop_done
    item = shift iterator
    res = concat item, res
    goto each_loop
  each_loop_done:
    .return(res)
.end