Visit all the children of the node with the visitor v

Property definitions

nitcc_runtime $ Node :: visit_children
	# Visit all the children of the node with the visitor `v`
	protected fun visit_children(v: Visitor)
	do
		for c in children do if c != null then v.enter_visit(c)
	end
lib/nitcc_runtime/nitcc_runtime.nit:376,2--380,4