code: Node createThisAliasReferenceForFunction(String aliasName, Node functionNode) {
      final Node result = IR.name(aliasName);
      if (isAddingTypes()) {
        result.setJSType(getTypeOfThisForFunctionNode(functionNode));
      }
      return result;
    }
docs: Creates a NAME node having the type of "this" appropriate for the given function node.