export deleteFunction in torch/csrc/autograd/function.h (#22236)
Summary:
In `torch/csrc/autograd/function.h` we define `torch::autograd::Function`, a (the?) central autograd record-holding class. `Function` is declared public API (`TORCH_API`).
We also define a custom deleter `deleteFunction` which we use throughout PyTorch's own use of `Function`. This trivial PR declares the deleter public API as well.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/22236
Differential Revision: D16001335
Pulled By: yf225
fbshipit-source-id: 6ef0a3630e8f82f277a0e6e26cc64455ef7ee43e
