Fix calculation of bounding boxes for non-4 component attributes
Fix calculation of bounding boxes for non-4 component attributes

* If we only have 3 or 2 components, set the remaining bounding box values to 0
  so they aren't set at +/- FLT_MAX.

baldurk/renderdoc,Zorro666/renderdoc,TurtleRockStudios/renderdoc_public,TurtleRockStudios/renderdoc_public,TurtleRockStudios/renderdoc_public,TurtleRockStudios/renderdoc_public,baldurk/renderdoc,Zorro666/renderdoc,baldurk/renderdoc,Zorro666/renderdoc,TurtleRockStudios/renderdoc_public,Zorro666/renderdoc,Zorro666/renderdoc,TurtleRockStudios/renderdoc_public,baldurk/renderdoc,Zorro666/renderdoc,baldurk/renderdoc,baldurk/renderdoc