Exit the program with a message

Property definitions

nitc $ NaiveInterpreter :: fatal
	# Exit the program with a message
	fun fatal(message: String)
	do
		var node = current_node
		if node == null then
			print message
		else
			node.fatal(self, message)
		end
		exit(1)
	end
src/interpreter/naive_interpreter.nit:431,2--441,4