Publish torch::Dict and torch::OperatorKernel (#20723)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/20723
These classes already existed but only as c10::Dict and c10::OperatorKernel.
Since they're now part of torch::RegisterOperators(), they should also live in the torch namespace.
Differential Revision: D15421575
fbshipit-source-id: d64ebd8664fadc264bbbae7eca1faa182529a32b
