[libcxx-commits] [libcxx] [libc++] fixing missing forward declarations of uses_allocator_construction_args (PR #67044)

[Louis Dionne via libcxx-commits]

ldionne wrote:

Also, this should probably be rebased on top of #66939 once it lands -- I think it'll be easier to do that than the other way around.

https://github.com/llvm/llvm-project/pull/67044