'3d and 0d tests for hstack(), vstack(), dstack().'

def check_xxstack(self, pyfunc, cfunc):

    def generate_starargs():
        (yield ())
    self.check_3d(pyfunc, cfunc, generate_starargs)
    a = np.array(42)
    b = np.array((-5j))
    c = np.array(True)
    self.check_stack(pyfunc, cfunc, (a, b, a))
