[llvm] [z/OS] Add z/OS archive reading support (PR #187110)

[James Henderson via llvm-commits]

https://github.com/jh7370 commented:

I've not reviewed the tests yet (I'm out of time today). I am a little concerned by a couple of things:

1) I don't like the use of canned binaries and we generally try to avoid them for newer tests (they're unreviewable and unmaintainable, plus permanently bloat the git repository size). Can we achieve the same goal via some other mechanism, e.g. generating them on the fly?

2) There seems to be inadequate test coverage of all the new code paths. I'd expect everything introduced to be tested.

https://github.com/llvm/llvm-project/pull/187110