Summary:
1. `noexcept` was missing from `unique_ptr` constructors leading to compilation errors in some edge cases
2. In case `unique_ptr` specified custom deleter with custom `deleter::pointer`, there could be compilation errors due to invalid cast from `deleter::pointer` to `void*`. Add extra overload of `model_set` to prevent this issue
Reviewed By: jberdine
Differential Revision: D5147071
fbshipit-source-id: 2586701