Tracks device where memory is allocated, pinned-host or device, and
more.
Uses memory-range-based lookups - so pointers that exist anywhere in
the range of hostPtr + size will find the associated AmPointerInfo.
The insertions and lookups use a self-balancing binary tree and
should support O(logN) lookup speed.
[ROCm/hip commit: 4ee2a5229b]
Ben Sander
Aditya Avinash Atluri
Jack Chung