[llvm] [dsymutil] Add option to copy swiftmodules built from interface (PR #165293)

[Adrian Prantl via llvm-commits]

https://github.com/adrian-prantl approved this pull request.

I'm going to accept the patch with the caveat that we're planning to remove the entire feature from dsymutil after a transition period. See my other comment. Feel free to reach out to me with any questions/concerns!

https://github.com/llvm/llvm-project/pull/165293