[functorch] Add some more view+inplace grad+vmap tests (#83176)
PyTorch autograd turns view+inplace into some sequence of as_strided and
a special CopySlices node. This PR:
- adds a test for that (`test_inplace_on_view`)
- modifies some other testing that also tests this behavior
(`test_inplace_view`, `test_inplace_manyview`) to also test
non-contiguous inputs.
Test Plan:
- wait for tests
Pull Request resolved: https://github.com/pytorch/pytorch/pull/83176
Approved by: https://github.com/Chillee
