This change moves option-related code from clangDriver into a new clangOptions library. This refactoring is part of a broader effort to support driver-managed builds for compilations using C++ named modules and/or Clang modules. It is required for linking the dependency scanning tooling against the driver without introducing cyclic dependencies, which would otherwise cause build failures when dynamic linking is enabled. In particular, clangFrontend must no longer depend on clangDriver for this to be possible. This PR is motivated by the following review comment: https://github.com/llvm/llvm-project/pull/152770#discussion_r2430756918