const runtime.traceArgCountShift

5 uses

	runtime (current package)
		trace.go#L98: 	traceArgCountShift = 6
		trace.go#L430: 		data = append(data, traceEvFrequency|0<<traceArgCountShift)
		trace.go#L565: 	buf.byte(ev | narg<<traceArgCountShift)
		trace.go#L655: 	bufp.byte(traceEvBatch | 1<<traceArgCountShift)
		trace.go#L873: 			buf.byte(traceEvStack | 3<<traceArgCountShift)