Shim caffe2 GetRepeatedArgument helper for use with Ivalue (#16519)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16519
GetRepeatedArguments is needed for some ops
Reviewed By: dzhulgakov
Differential Revision: D13864293
fbshipit-source-id: a39255cd391c28acd75a6f0e81d558542417e032
