My interpretation of this: building_grid_bit_shift == log2(build_grid_size).The log2 of grid size of the building.
Expected:
- build_grid_size == 1 => building_grid_bit_shift == 0
- build_grid_size == 2 => building_grid_bit_shift == 1
- build_grid_size == 256 => building_grid_bit_shift == 8

