Implement multiple dispatch in boxed c10 dispatcher (#26118)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/26118
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Test Plan: Imported from OSS
Differential Revision: D17404367
Pulled By: ezyang
fbshipit-source-id: 14a16baa4b59f97182725092531a54603f3d92b8
