'Create an incoming variable (due to not enough values being
available on our stack) and request its assignment from our
incoming blocks\' own stacks.'

def make_incoming(self):

    assert self.incoming_blocks
    ret = self.make_temp('phi')
    for ib in self.incoming_blocks:
        stack_index = (self.stack_offset + self.stack_effect)
        ib.request_outgoing(self, ret, stack_index)
    return ret
