def gen_ivar_list!(c_node, off:)
      c_node.ivar_list.each do |ivar_node|
        emit! "@#{ivar_node.name}: any\n", off: off
      end
    end
def gen_ivar_list!(c_node, off:)
      c_node.ivar_list.each do |ivar_node|
        emit! "@#{ivar_node.name}: any\n", off: off
      end
    end
NOTE: In current impl, ivar's type is declared as any

 @param [AST::ClassNode] c_node
 @param [Integer] off
 @return [void]