Obscure detail in that if you teleport right on a chunk line, it
adds +1 to your collision check and will check the unloaded neighbor.
but the call to load the chunk then returned null if it was pending unload, such
as the load we did in Player List
However we want gen=true for players here anyways, so use getType
While there is more down the collision system, remove some of the wrapping
Spliterator stuff as even this wrapper stream has shown up in profiling.
With other collision optimizations, we might also even avoid inner streams too.