[clang] [LinkerWrapper] Extend with usual pass options (PR #96704)

[Joel E. Denny via cfe-commits]

jdenny-ornl wrote:

> Makes sense overall. However in the future I'm looking to move away from the home-baked LTO pipeline in favor of giving it to the linker. That allows me to set up libraries as a part of the target toolchain in the driver. I guess for that I'll just need to forward `-mllvm` to the internal clang invocation.

As long as there's some way to inject an LLVM pass plugin at link time (even if it requires -flto or -foffload-lto), that's fine.  I don't know that a stable command-line interface is critical at this point.  Of course, please ping me if it changes.

https://github.com/llvm/llvm-project/pull/96704