ctc loss no batch dim support (#70092)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/70092
Test Plan: Imported from OSS
Reviewed By: jbschlosser
Differential Revision: D33280068
Pulled By: george-qi
fbshipit-source-id: 3278fb2d745a396fe27c00fb5f40df0e7f584f81
