'Test bug that decref the iterator early.
If the bug occurs, a segfault should occur'

def test_loop_nest(self):

    pyfunc = loop_nest_3
    cres = compile_isolated(pyfunc, (), flags=forceobj)
    cfunc = cres.entry_point
    self.assertEqual(pyfunc(5, 5), cfunc(5, 5))
    def bm_pyfunc():
        pyfunc(5, 5)
    def bm_cfunc():
        cfunc(5, 5)
    print(utils.benchmark(bm_pyfunc))
    print(utils.benchmark(bm_cfunc))
