code: Node createFor(Node init, Node cond, Node incr, Node body) {
      return IR.forNode(init, cond, incr, body);
    }
docs: Returns a new FOR node.
  
  <p>Blocks have no type information, so this is functionally the same as calling {@code
  IR.forNode(init, cond, incr, body)}. It exists so that a pass can be consistent about always
  using {@code AstFactory} to create new nodes.