[llvm-objcopy] Support --{enable,disable}-deterministic-archives

Summary: ar and objcopy/strip all support configuring whether archives are written deterministically (timestamps/UIDs/GIDs/etc zero'd). This has been ported to llvm-ar (the U/D modifiers) but not yet to llvm-objcopy/strip.

Reviewers: jakehehrlich, jhenderson, alexshap

Reviewed By: jhenderson

Subscribers: ruiu, mgrang, llvm-commits

Differential Revision: https://reviews.llvm.org/D53913

llvm-svn: 345859