[llvm] [bazel] Introduce config setting to enable clang proto fuzzer targets (PR #123833)

[NAKAMURA Takumi via llvm-commits]

chapuni wrote:

@rupprecht I'd like to use `//clang:all` for my private builder not to miss newly added targets.
That said, protobuf stuff is not in my scope. I don't want to append rules in my WORKSPACE for that.

For me, it'd be better if I could specify like `-//clang/clang-fuzzer/...`.

protobuf doesn't prevent my build when I build "clang toolchains" with the explicit target. So, easy exclusions would not be necessary if you don't want to involve complexity at the moment.

https://github.com/llvm/llvm-project/pull/123833