Ant Attack: Routine at 88D0

88D0: Go up a block, if there is room

Used by the routines at MOVE_OBJECT and BITTEN.
RISE	88D0	LD D,H	Blocked above: walk instead.
	88D1	LD E,L
	88D2	LD A,C
	88D3	INC A
	88D4	CALL TEST_MAP_BIT
	88D7	JP C,MOVE_OBJECT_1
	88DA	INC C
	88DB	LD (IX+$02),C
	88DE	RET