I dont know the why, but the problem lies in the start on the handle_gravity
function in the results to the c_scan.

From memory of my conversion then testing this code, this c_scan generates
different returns in WDL and c-lite, which doesnt make sense to me.
In WDL, it returns a -quants_depth if the object passes through the floor.
In lite-c, it returns a -1400 and something if the object passes through the floor.
I dont know why. But this same seemingly-wrong return value does cause problems
elsewhere in KHmovement, but minor compared to the gravity issue.