port //c10/macros to common build structure (#70852)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70852
This is the first change that uses a common build file, build.bzl, to
hold most of the build logic.
ghstack-source-id: 147170895
Test Plan: Relying on internal and external CI.
Reviewed By: malfet
Differential Revision: D33299331
fbshipit-source-id: a66afffba6deec76b758dfb39bdf61d747b5bd99
(cherry picked from commit d9163c56f55cfc97c20f5a6d505474d5b8839201)
