[libc++] Add _LIBCPP_NODEBUG on internal allocator trait aliases (#118835)

Put _LIBCPP_NODEBUG on the new allocator trait aliases introduced in
https://github.com/llvm/llvm-project/pull/115654. This prevents a large
increase in the gdb_index size that was introduced by that PR.

GitOrigin-RevId: 384e69a914558899a35f13349965966de2d635ac
2 files changed