shape inference for learning rate op (#20020)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/20020
Add shape inference for LearningRate op. The output (lr) should have similar shape with input (iteration), but not the same type (float vs int).
Reviewed By: un-disclosed
Differential Revision: D15112300
fbshipit-source-id: 09969aefa15172a6f3c70cd9b2548e3020da5d7a
