[libcxx-commits] [libcxx] [libc++] Regenerate transitive include. (PR #202001)

[A. Jiang via libcxx-commits]

frederick-vs-ja wrote:

> I'm a bit confused by the `only if` logic. This PR doesn't add new headers; it simply updates the existing ones.

I meant that we need to test transitive inclusion in some mode in this way only if we want to support including relevant headers in that mode. Also, changes to CSV files won't be verified if we don't remove `c++03, c++11, c++14, c++17` from `UNSUPPORTED`.

https://github.com/llvm/llvm-project/pull/202001