Happens when device runs out of memory and Cycles is moving some
textures to the host memory.

The delayed memory free for OptiX BVH was moving data from one
device_memory to another, leaving the original device memory in
an invalid state. This was ruining the allocation map in the CUDA
device which is using pointer to the device_memory.

This change makes it so the memory pointer is stolen from BVH
into the delayed memory free list.

Additionally, forbid copying and moving instances of device_memory
and added sanity checks in the device implementation.