Back out "Horizontally fuse input concatenation (#108115)" (#108793)
Summary:
Original commit changeset: f15956d96311
Original Phabricator Diff: D48996091
Test Plan: Reverting to Unbreak test
Differential Revision: D49065517
Pull Request resolved: https://github.com/pytorch/pytorch/pull/108793
Approved by: https://github.com/Chillee
