[llvm] [test][llvm-objdump][AArch64] Add tests for ELF AUTH constants (PR #74298)

[Fangrui Song via llvm-commits]

MaskRay wrote:

> Rebased and force-pushed to trigger buildkite (builds were red previously since being dependent on #74874). @metaflow As far as I understood, there is currently no way to trigger pre-merge checks without updating the branch - please provide a way for that since updating the branch via rebase + force-push when the build fails due to unrelated reasons clutters review history. Thanks!

I think rebasing while keeping all the incremental changes as "Commits" in the tab does not seem to clutter review history.

https://github.com/llvm/llvm-project/pull/74298