Decompose/add reference for `view_as_complex` (#108005)
Aten source: https://github.com/pytorch/pytorch/blob/d4a99631dd589afbb972b3401e56f029192c9b0f/aten/src/ATen/native/ComplexHelper.h#L78
Documentation reference:
https://pytorch.org/docs/stable/generated/torch.view_as_complex.html
Note: this adds a new primitive `view_of_dtype`, which is trivially implemented, as its meta function is already implemented elsewhere.
Finally, this is not registered as a decomposition (yet), because TorchInductor does not yet support complex types. It should be added once we do.
Closes https://github.com/pytorch/pytorch/issues/108020 as well.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/108005
Approved by: https://github.com/peterbell10, https://github.com/ezyang
