Revert D31732418: Add support for multi output nodes in partial eval graph stitching
Test Plan: revert-hammer
Differential Revision:
D31732418 (https://github.com/pytorch/pytorch/commit/0fdc9b77a3502de95eac5c42d83940c6af415616)
Original commit changeset: 767698d031b1
fbshipit-source-id: f899eb155dcec67d57f53a658a71169d37b63b42
