The expression made safe

Property definitions

	# The expression made safe
	var n_expr: AExpr is writable, noinit

src/parser/parser_nodes.nit:2791,2--2792,38

	redef fun n_expr=(node)
	do
		_n_expr = node
		node.parent = self
	end

src/parser/parser_prod.nit:7434,2--7438,4