Revert D34524207: [pytorch][PR] remove _s_where
Test Plan: revert-hammer
Differential Revision:
D34524207 (https://github.com/pytorch/pytorch/commit/4eb248256801103b08726bf5d85496641cebcdbb)
Original commit changeset: bc71e27b6d3f
Original Phabricator Diff: D34524207 (https://github.com/pytorch/pytorch/commit/4eb248256801103b08726bf5d85496641cebcdbb)
fbshipit-source-id: 87b1220d851c3d2b51bdd1cf2f8a493c58ab9b14
(cherry picked from commit af1f0cc9e032b00619a7979bbbd2281f69e0fdf0)
