**Dynamo**
We don't want setattr in the graph. Setting data has interesting implications on both aliasing and on the autograd engine.
The safe recipe is:
1) Disable grad
2) Call set_()
3) Manually lower the version counter on the object to hide it from the autograd engine
This is effectively the same exact thing as setting .data, and it composes properly with aot_autograd and inductor.
**aot_autograd**
For aot_autograd, there's another snag.
Specifically, when we invoke aot_autograd, we call `fake_mode.from_tensor()`, relying on memo to get the right tensor out. For .data mutations, this doesn't work, because the memoized fake_tensor is in the state it will be in at the end of the trace, not at the beginning. This means that the .data call is already applied, and the tensor shape (as in the case of these tests) mismatches. aot_autograd produces an invalid graph, with illegal calls like `torch.ops.aten.view.default(primals_2, [0])` where primals is actually sized `([6])` on input.
The new plan here is to:
1) Record tensor fakification policy in dynamo
2) provide a fresh fake mode to all backends
3) Invoke from_tensor with the stored policy to get fresh new fake tensors in aot_autograd
Pull Request resolved: https://github.com/pytorch/pytorch/pull/113080
Approved by: https://github.com/bdhirsh
