[llvm-objcopy/llvm-strip]: handle --version

Summary:
Implement --version for objcopy and strip.

I think there are LLVM utilities that automatically handle this, but that doesn't seem to work with custom parsing since this binary handles both objcopy and strip, so it uses custom parsing.

This fixes PR38298

Reviewers: jhenderson, alexshap, jakehehrlich

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D52328

llvm-svn: 342702