“29c19e4411befa52dd4c303a21c49aa52749a372”上不存在“mobile/test/operators/test_prior_box_op.cpp”
* Rewrite is_empty op to avoid unnecessary data transform. test=develop * Add the implementation of InferShape and InferVarType for is_empty op. test=develop * Rewrite is_empty op to avoid directly inherit OperatorBase. test=develop