extract out //c10/core:alignment (#70858)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70858
ghstack-source-id: 147642533
Test Plan: Extracted a constant to a new header, trusting CI build to validate.
Reviewed By: malfet
Differential Revision: D33329689
fbshipit-source-id: 8697bb81a5cc3366462ebdf1f214b62d478fa77c
(cherry picked from commit 16663847e179ea1c2a16f2bb538cfe3aca032593)
