What 505 is saying is that the MiG-29 can use the IRST to track targets without switching on the radar. It could also mean an increase in base accuracy since there wouldn't be much opportunity for countermeasures.
The MiG-29M was supposed to carry a laser designator under the fuselage but this was shelved in favour of the Su-27IB or Su-34 as it is now. There is one attached to the IRST but that faces forward and is therefore unsuitable for LGBs. It can use the KAB-500Kr and Kh-31, or anything else in the Soviet inventory.