[libcxx-commits] [libcxx] [libc++] Revert removal of <movable_box.h> to fix lldb test failure (PR #140960)

[Louis Dionne via libcxx-commits]

ldionne wrote:

As said in https://github.com/llvm/llvm-project/issues/137046#issuecomment-2918689645, I think we might as well mark the failing test as unsupported in LLDB. And then we remove the `UNSUPPORTED` annotation once the bug is fixed.

So I'm not sure we need to actually land this change.

https://github.com/llvm/llvm-project/pull/140960