I would guess those need to change to something like this:
Code:
spells.cpp(1468): group_id_caster = GetRaid()->GetGroup(CastToClient());
spells.cpp(1480): group_id_caster = owner->GetRaid()->GetGroup(owner->CastToClient());
spells.cpp(1492): group_id_target = spell_target->GetRaid()->GetGroup(spell_target->CastToClient());
spells.cpp(1504): group_id_target = owner->GetRaid()->GetGroup(owner->CastToClient());
But I'm not sure if what GetGroup() returns is actually the right type of value. Hopefully the person that made the checkin will fix it, because it wouldn't compile for them either unless they changed something else and didn't check that in.