[llvm-objcopy] Add --add-gnu-debuglink

This change adds support for --add-gnu-debuglink to llvm-objcopy

Differential Revision: https://reviews.llvm.org/D41731

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323477 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed