allocation: Allow copies from raw pointers and std::vector
allocation: Allow copies from raw pointers and std::vector

Enable allocation::copy() to copy data from raw CPU or GPU pointers, as
well as host-side std::vector containers.

nsubtil/lift,chuckseberino/lift,chuckseberino/lift,chuckseberino/lift,nsubtil/lift,nsubtil/lift