[FX] Rename reduce functions back to their old, public names (#64324)
Summary:
Unfortunately pickle serializes the names of these functions. Also put them under backward-compatibility enforcement.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/64324
Test Plan: Local repro https://fb.workplace.com/groups/3440841732711443/permalink/4018921611570116/
Reviewed By: SplitInfinity, TailofJune
Differential Revision: D30684185
Pulled By: jamesr66a
fbshipit-source-id: 900701220155d15115cd0c07cf7774a2891bd04f
