[lld] [lld] Add explicit conversion for enum to Twine. (PR #100627)

[Scott Todd via llvm-commits]

ScottTodd wrote:

Thanks for the quick review! Confirmed that our downstream build (using clang-9) was successful with this patch: https://github.com/iree-org/iree/actions/runs/10099225942/job/27927980200?pr=18004

https://github.com/llvm/llvm-project/pull/100627