C++ API: torch::nn::Softmax (#27446)
Summary:
Add torch::nn::Softmax module support for the C++ API
Related Issue: https://github.com/pytorch/pytorch/issues/25883
Reviewer: yf225
Pull Request resolved: https://github.com/pytorch/pytorch/pull/27446
Differential Revision: D17839546
Pulled By: yf225
fbshipit-source-id: 7c7fb55111b261614de7c3a75fa1019fbde93c67
