Reorder dispatcher/legacy_dispatcher types (#45973)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/45973
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Test Plan: Imported from OSS
Reviewed By: smessmer
Differential Revision: D24163527
Pulled By: ezyang
fbshipit-source-id: 2631a2ccd7ab525fe32fa56192ded4ff7ac3723f
