[libcxx-commits] [libcxx] [libc++] Prepare for PR #134330 by migrating to std::__static_fancy_pointer_cast (PR #180546)

[Nikolas Klauser via libcxx-commits]

https://github.com/philnik777 approved this pull request.

I don't really like this, but I don't want to block the follow-up patch on whether we can drop `__static_fancy_pointer_cast` somehow.

https://github.com/llvm/llvm-project/pull/180546