[libcxx-commits] [libcxx] [libc++][C++03] Split libc++-specific tests for the frozen headers (PR #144093)

[Louis Dionne via libcxx-commits]

https://github.com/ldionne requested changes to this pull request.

Let's remove all of the tests that contain `UNSUPPORTED: c++03` from this patch to make it easier to review.

https://github.com/llvm/llvm-project/pull/144093