[libcxx-commits] [libcxx] [libcxx][test] Avoid warnings about unused variables and typedefs if `_LIBCPP_VERSION` is not defined (PR #155679)

[Alex Guteniev via libcxx-commits]

AlexGuteniev wrote:

> @AlexGuteniev Do you need the branch to be merged?

Yes, please

https://github.com/llvm/llvm-project/pull/155679