Same idea as in #134723 - flatten indirect call info in `"VP"` `MD_prof` metadata for the thinlinker, for cases that aren't covered by a contextual profile. If we don't ICP an indirect call target in the specialized module, the call will fall to the copy of that target outside the specialized module. If the graph under that target also has some indirect calls, in the absence of this pass, we'd have a steeper performance regression - because none of those would have a chance to be ICPed.