Summary:
Allow strip to be called on multiple input files, which is interpreted as stripping N files in place. Using multiple input files is incompatible with -o.
To allow this, create a `DriverConfig` struct which just wraps a list of `CopyConfigs`. objcopy will only ever have a single `CopyConfig`, but strip will have N (where N >= 1) CopyConfigs.
Reviewers: alexshap, jakehehrlich
Reviewed By: alexshap, jakehehrlich
Subscribers: MaskRay, jakehehrlich, llvm-commits
Differential Revision: https://reviews.llvm.org/D51660
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341464 91177308-0d34-0410-b5e6-96231b3b80d8
