[llvm] [llvm-ar] Enable failed testacase on FreeBSD (PR #192612)

[James Henderson via llvm-commits]

jh7370 wrote:

I've added a couple more reviewers from the original patch review in case they have comments. @emaste / @arichardson, do you have anything to add?

https://github.com/llvm/llvm-project/pull/192612