Add extra_info to test_bench.py reports (#1032)
Summary:
This makes the test_bench.py reports more consistent with those from run_sweep.py
Pull Request resolved: https://github.com/pytorch/benchmark/pull/1032
Reviewed By: FindHao
Differential Revision: D37857780
Pulled By: xuzhao9
fbshipit-source-id: a88d3e099f3cfb7f45486c12cffa3ca370ef6634
