Trim libshm deps, move tempfile.h to c10 (#17019)
Summary:
libshm_manager doesn't need to depend on all of libtorch. It only uses tiny tempfile.h which can be moved to c10. I could just duplicate the file too, but it's not worth it as c10 is small enough.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/17019
Differential Revision: D14052688
Pulled By: dzhulgakov
fbshipit-source-id: 8797d15f8c7c49c49d40b7ab2f43aa3bf6becb0c
