[libunwind][NFC] Suppress unused parameter warnings

Reviewers: EricWF

Subscribers: christof, chrib, dexonsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D52393

llvm-svn: 342811
GitOrigin-RevId: 2e667527c5672150572be1b344d58a95ef03e732
1 file changed