Fix CreateTest
Fix CreateTest

Summary:
Looks like they fixed this nasty corner case in c++20, as the create code requires that the native type provide a default constructor.
This would also be solved by allowing a custom Adapter::create, so I've left TODOs.

Reviewed By: thedavekwon

Differential Revision: D35636224

fbshipit-source-id: c5d53375399b7c40f2f9019e4a2ccab9d876c528

facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift