Revert D33281300: Prevent sum overflow in broadcast_object_list
Test Plan: revert-hammer
Differential Revision:
D33281300 (https://github.com/pytorch/pytorch/commit/807f9a828cb841b5688cf0011e49994ac58a87c1)
Original commit changeset: 1bc83e8624ed
Original Phabricator Diff: D33281300 (https://github.com/pytorch/pytorch/commit/807f9a828cb841b5688cf0011e49994ac58a87c1)
fbshipit-source-id: beb81a9cbfba405a61b11dfaa8e39c9601f45643
