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

[via llvm-commits]

jathu wrote:

@aeubanks 

> I still think this points to wanting a more complete solution where we properly mirror the upstream build directory.

Seems like this large effort can only be accomplished by the team at Google. Would this be prioritized at all by the Bazel/Clang team? This will ladder up to having a true hermetic C++ build environment

> I don't think it makes sense to add in a workaround just for clang-tidy if clang doesn't even work.

Please help me understand the reasoning behind this — this change is relatively independent to the rest of the llvm repo. It primarily exists (based on the mirror) to support clang-tools-extra. The change is pretty benign considering it's just symlinking a tree without affecting the source

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If this proposed change is a hard no, is there a way to get clang-tidy to work in its current state? I've tried various attempts (https://github.com/llvm/llvm-project/issues/63890), and it doesn't seem possible.

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