waits until ly=151
sets lyc to 0
enables lyc int
enables mode2 int
waits for int

on int:
jumps to 0x1000
lots of nops
reads IF
outputs value of IF&3

DMG-08 / CGB:
lyc0m2int_m2irq_1.gb should output 0
lyc0m2int_m2irq_2.gb should output 2