Platforms: linux

This test was disabled because it is failing on master ([recent examples](http://torch-ci.com/failure/test_torch.py%3A%3ATestTorch%3A%3Atest_equal)).

The cause seems to point to https://github.com/pytorch/pytorch/pull/100024 (or D45282119 as it was landed internally)

cc @mruberry @houseroad @ezyang 
torch.tensor([1]).unflatten(0, [2, 2])
        with self.assertRaisesRegex(IndexError, r"Dimension specified as 0 but tensor has no dimensions"):
            torch.tensor(1).unflatten(0, [0])
        with self.assertRaisesRegex(RuntimeError, r"only one dimension can be inferred"):
            torch.randn(5, 10).unflatten(1, (-1, -1))
        with self.assertRaisesRegex(RuntimeError,
                                    r"Provided sizes \[-1, 4\] don't multiply up to the size of dim 1 \(10\)"):
            torch.randn(5, 10).unflatten(1, (-1, 4))
        with self.assertRaisesRegex(RuntimeError,
                                    r"the unspecified dimension size -1 can be any value and is ambiguous"):
            torch.randn(2, 0).unflatten(1, (2, -1, 0))
    
    def test_warn_s(self):
        test_s = [
            
            (torch._C._warn, UserWarning, r"Test message for TORCH_WARN"),
            (torch._C._warn_deprecation, DeprecationWarning, r"Test message for TORCH_WARN_DEPRECATION"),
        ]
        for fn, warning_, message in test_s:
            with warnings.catch_warnings(record=True) as w:
                warnings.resetwarnings()
                warnings.filterwarnings('always', category=warning_)
                fn()
                self.assertEqual(len(w), 1, msg=f'{warning_} not raised')
                warning = w[0].message
                self.assertTrue(isinstance(warning, warning_), msg=f'{warning_} not raised')
                self.assertTrue(re.search(
                    message,
                    str(warning)))
    def test_structseq_repr(self):