* Thrust 1.17 removes the experimental/pinned_allocator.
When xgboost is brought into a large project it can
be compiled against Thrust 1.17+ which don't offer
this experimental allocator.
To ensure that going forward xgboost works in all environments we provide a xgboost namespaced version of
the pinned_allocator that previously was in Thrust.
* Update gputreeshap to work with libcudacxx 1.9
