[llvm] [llvm-objdump] Handle -M for --macho (PR #113795)

[James Henderson via llvm-commits]

https://github.com/jh7370 approved this pull request.

LGTM, on the assumption that the `-M` option has an impact on the output displayed in the test (so we'd know if it wasn't doing anything in the future).

https://github.com/llvm/llvm-project/pull/113795