Redefine Struct.new(...).new

This should not reuse Struct.new, but fall back to the original
constructor instead.

src/struct.rb

@@ -214,6 +214,10 @@ def self.new(*attrs, &block)
         Struct.const_set(klass, result)
       end
 
+      def result.new(...)
+        Object.method(:new).unbind.bind(self).call(...)
+      end
+
       result
     end
   end