[libcxx-commits] [libcxx] [libc++] Remove workaround which allows setting _LIBCPP_OVERRIDABLE_FUNC_VIS externally (PR #113139)

[Louis Dionne via libcxx-commits]

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

LGTM, but please make sure to include the explanation for the history of this change in the PR description (i.e. the commit message once landed).

https://github.com/llvm/llvm-project/pull/113139