states := make(map[GoID]GoState)
	bgMark := make(map[GoID]bool)
	procs := []procsCount{}
	seenSync := false

	// Helpers.
	handleSTW := func(r Range) bool {
		return flags&UtilSTW != 0 && isGCSTW(r)
	}
	handleMarkAssist := func(r Range) bool {
		return flags&UtilAssist != 0 && isGCMarkAssist(r)
	}
	handleSweep := func(r Range) bool {
		return flags&UtilSweep != 0 && isGCSweep(r)
	}