const runtime.mSpanDead

5 uses

	runtime (current package)
		mgcsweep.go#L732: 		s.state.set(mSpanDead)
		mheap.go#L353: 	mSpanDead   mSpanState = iota
		mheap.go#L1664: 	s.state.set(mSpanDead)
		mheap.go#L1718: 	span.state.set(mSpanDead)
		traceallocfree.go#L54: 		if s.state.get() == mSpanDead {