[libcxx-commits] [libcxx] Revert "[libc++] Allow the use of extensions in the implementation (#79532)" (PR #85792)

[Nikolas Klauser via libcxx-commits]

philnik777 wrote:

#85917 is an (IMO simpler) alternative to work around this problem.

https://github.com/llvm/llvm-project/pull/85792