[llvm] [NFC][BOLT] Make file-local cl::opt global variables static (PR #126472)

[Paschalis Mpeis via llvm-commits]

https://github.com/paschalis-mpeis approved this pull request.

Thanks for addressing that. Let's wait for tests to pass again, and then probably @maksfb can hit merge.

https://github.com/llvm/llvm-project/pull/126472