add ZERO_COLLISION_HASH to caffe2 data type (#30912)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/30912
Add a new data type ZERO_COLLISION_HASH .
Test Plan: ci
Reviewed By: boryiingsu
Differential Revision: D18843626
fbshipit-source-id: b2d8280f13c78b4a656cf95822198df59de7b64c
