Used by the routines at DRAW_OBJECT and SPRITE_SHIFTED_RUN.

The row count goes to A', and A takes the first buffer byte: the shifted units of SPRITE_SHIFTED_RUN expect the byte they are finishing to be in A already. The JR's offset is patched by DRAW_OBJECT for every sprite, into the aligned run at SPRITE_ALIGNED_RUN or the shifted one at SPRITE_SHIFTED_RUN; as it stands in the listing, an offset of $FE, it is a JR to itself.