const runtime.traceEvGoLabel

2 uses

	runtime (current package)
		traceevent.go#L77: 	traceEvGoLabel         // apply string label to current running goroutine [timestamp, label string ID]
		traceruntime.go#L436: 		w.event(traceEvGoLabel, trace.markWorkerLabels[tl.gen%2][pp.ptr().gcMarkWorkerMode])