[llvm] [SystemZ][z/OS] Add goffdumper/llvm-readobj tools (PR #71071)

[James Henderson via llvm-commits]

https://github.com/jh7370 commented:

You should really try to avoid canned object files in the repository, because thwey are opaque and it's not clear what in them us important for testing them. They also don't play well with source control (you can't diff a binary file). A better approach would be to generate the object at test time. From most preferable to least, you could use a) yaml2obj, b) assembly and llvm-mc, or c) IR and llc. I expect yaml2obj doesn't support GOFF yet, but adding that support will be highly worthwhile if you plan on adding readobj and other tool support, because it allows you fine-grained control of your test inputs, allowing you to more easily test edge cases (especially for error handling).

You should also break this PR into multiple. The first would do nothing except add the bare framework for GOFF files, and the rest should add one feature (symbol dumping, section dumping etc) at a time.

https://github.com/llvm/llvm-project/pull/71071