[clang] [clang] CWG150: add tests and change to unreleased (PR #93758)

[Vlad Serebrennikov via cfe-commits]

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

You should apply the suggested change, and run `make_cxx_dr_status` script. I don't expect it to introduce new changes, though, but we should be on a safe side here, and not rely on manual editing of `cxx_dr_status.html`.

https://github.com/llvm/llvm-project/pull/93758