[llvm] [Bazel] Support opt-driver library, like clang-driver (PR #79205)

[Eli Friedman via llvm-commits]

efriedma-quic wrote:

Looks okay to me, but I'm a bit worried there's something I'm missing, so I'd like a second reviewer to chime in.

https://github.com/llvm/llvm-project/pull/79205