OpInfos for torch.{flatten, column_stack} (#69237)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/69237
Test Plan: Imported from OSS
Reviewed By: mruberry
Differential Revision: D32988956
Pulled By: anjali411
fbshipit-source-id: b7f5c537ff9731f56232aa5647910f03edf4582a
