extract out //c10/core:alloc_cpu (#70859)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70859
ghstack-source-id: 147642534
Test Plan: Extracting code unmodified to a new library: relying on CI to validate.
Reviewed By: malfet
Differential Revision: D33329688
fbshipit-source-id: f60327467d197ec1862fb3554f8b83e6c84cab5c
(cherry picked from commit f82e7c0e9beba1113defe6d55cf8a232551e913b)
