DSZ3 boss' shockwaves glitch out when too far from the map origin

If a shockwave object is more than 16384 fracunits away from the map origin, the function that spawns intermediary shockwave objects will glitch out, often spawning many more objects than needed in the wrong places.

This can slow the game down to a grind, as there's no limit to the amount of objects that will be spawned.

Here's a test map, which is an edit of DSZ3 that has center of the arena at -16384, 16384: shockwave.wad