[llvm] [llvm-exegesis] Fix musl build (PR #147954)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 approved this pull request.

LGTM.

I thought this got pulled with one of the pointer auth patch reverts, but apparently not. Thanks for the fix!

https://github.com/llvm/llvm-project/pull/147954