C++ make constructor NamedAnyModule(name,any) public (#36869)
Summary:
Allows creation of _NamedAnyModule_ directly from _AnyModule_, e.g.
```
auto a=torch::nn::AnyModule(torch::nn::Linear(1,2));
auto m=torch::nn::NamedAnyModule("fc", a);
```
Without the public constructor, it would be necessary to recast the AnyModule to underlying type,
then have the constructor cast it back to AnyModule.
With the public AnyModule constructor,
possible to do
```
auto q=Sequential({m});
```
or
```
q->push_back(m.name, m.module());
```
(works in conjunction with PR https://github.com/pytorch/pytorch/issues/36720 which allowed adding _AnyModule_ directly)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/36869
Differential Revision: D21110074
Pulled By: yf225
fbshipit-source-id: aaea02282b9024824785e54d8732c0a12c850977
