Pass F::*FuncOptions instead of torch::nn::*Options to functionals, and make F::*FuncOptions a different class when necessary (#29364)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/29364
Currently, we use `torch::nn::*Options` both as module options and functional options. However, this makes it very hard to manage the parameters in `torch::nn::*Options`, because a module's constructor can take a different set of arguments than the module's equivalent functional (e.g. `torch.nn.BatchNorm1d` takes `num_features, eps=1e-5, momentum=0.1, affine=True,
track_running_stats=True`, while `F::batch_norm` takes `running_mean, running_var, weight=None, bias=None, training=False, momentum=0.1, eps=1e-5`).
This PR resolves the above problem by making `F::*FuncOptions` a different class from `torch::nn::*Options` when necessary (i.e. when a module's constructor takes a different set of arguments than the module's equivalent functional). In the rest of the cases where the module constructor takes the same set of arguments as the module's equivalent functional, `F::*FuncOptions` is an alias of `torch::nn::*Options`.
Also as part of this PR, we change all functional options to pass-by-value, to make the semantics consistent across all functionals.
Test Plan: Imported from OSS
Differential Revision: D18376977
Pulled By: yf225
fbshipit-source-id: 8d9c240d93bfd5af0165b6884fdc912476b1d06b
