[llvm] [bazel] Add rules for clang-fuzzer protobuf-related libraries (PR #123126)

[NAKAMURA Takumi via llvm-commits]

chapuni wrote:

Could we split out clang-proto-fuzzer stuff into the directory (for me to exclude them easily)?

For now, I have:
```
    "- at llvm-project//clang:clang-fuzzer-initialize",
    "- at llvm-project//clang:clang-proto-to-cxx",
    "- at llvm-project//clang:cxx_cc_proto",
    "- at llvm-project//clang:cxx-proto",
    "- at llvm-project//clang:proto-to-cxx-lib",
```

https://github.com/llvm/llvm-project/pull/123126