[llvm] [Bazel][Clang Tidy] Include builtin headers with clang-tidy (PR #67626)

[Reid Kleckner via llvm-commits]

rnk wrote:

I think the important thing I want to get out of the review is agreement about the long term direction, and it sounds like @rupprecht 's solution is a good candidate.

If we agree on that, are folks OK approving this in the short term? Even if this clang-tidy symlink will be removed later, it doesn't seem like high interest tech debt.

https://github.com/llvm/llvm-project/pull/67626