Remove empty_like+fill from AOT Autograd graphs for nvFuser (#86908)
AOT Autograd records C++ code `1 - tensor` as a sequence of empty_like, fill, and sub (see https://github.com/pytorch/pytorch/issues/86612).
Both empty_like and fill are not supported yet. This PR is a workaround for enabling fusions of `silu_backward`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/86908
Approved by: https://github.com/ngimel