[llvm-objcopy] Add support for response files in llvm-strip and llvm-objcopy

Summary: Addresses https://bugs.llvm.org/show_bug.cgi?id=42671

Reviewers: jhenderson, espindola, alexshap, rupprecht

Reviewed By: jhenderson

Subscribers: seiya, emaste, arichardson, jakehehrlich, MaskRay, abrachet, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65372

llvm-svn: 371911