[jit] better message for bad type annotation (#47464)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47464
```
ValueError: Unknown type annotation: 'typing.Sequence[torch.Tensor]' at File "xxx.py", line 223
images = [x["image"].to(self.device) for x in batched_inputs]
images = [(x - self.pixel_mean) / self.pixel_std for x in images]
images = ImageList.from_tensors(images, self.backbone.size_divisibility)
~~~~~~~~~~~~~~~~~~~~~~ <--- HERE
return images
```
Otherwise have no clue where the error is.
Test Plan: sandcastle
Reviewed By: glaringlee
Differential Revision: D24764886
fbshipit-source-id: abd5734394e53b20baa6473134896e3a2b178662
