Remove copy and copy_ special case on Type (#18972)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18972
ghimport-source-id: b5d3012b00530145fa24ab0cab693a7e80cb5989
Differential Revision: D14816530
Pulled By: li-roy
fbshipit-source-id: 9c7a166abb22d2cd1f81f352e44d9df1541b1774
