return true
	})

	// Assign numbers to all the labels we observed.
	used := -1 // returns use -1
	for _, l := range labels {
		used -= 3
		r.branchNext[branch{syntax.Break, l}] = used
		r.branchNext[branch{syntax.Continue, l}] = used + 1
		r.branchNext[branch{syntax.Goto, l}] = used + 2
	}
}

// endLoop finishes the conversion of a range-over-func loop.