Used by the routine at ADJ_FOR_OUT_OF_BOUNDS.

Tries the object's box against all 54 records. For each one it already overlaps in V and Z, with the moves accepted so far, an overlap in U after the move means dU has to be shortened, a unit at a time, until the boxes no longer meet; if dU reaches zero the scan stops.

Every such meeting sets bit 0 of +$0C and passes harm between the two: bit 6 of +$0D means killed, and the obstacle gets it if the mover has bit 7 (kills what it moves into), the mover if the obstacle has bit 5 (kills what touches it). An obstacle that can be pushed (bit 2 of its +$07) is given the mover's whole intended dU, so it moves off on its own update.