dynamo: trace autograd.Function with tensor subclass input (#108093)
Summary:
Enables dynamo eager mode tracing for the following situation:
1. we have a torch.autograd.Function
2. the input to that function is a tensor subclass which is an intermediary
This is useful for float8 training UX.
Test Plan:
```
python test/dynamo/test_autograd_function.py -k intermediary_input
```
Reviewers:
Subscribers:
Tasks:
Tags:
Fixes #ISSUE_NUMBER
Pull Request resolved: https://github.com/pytorch/pytorch/pull/108093
Approved by: https://github.com/bdhirsh, https://github.com/wanchaol
