polymer-resin is incompatible with Polymer 3 modules

[gdmfilippov]

Hi,
The polymer-resin requires global Polymer variable to be set.
Polymer 3 doesn't set global Polymer variable. The recommended approach for Polymer 3 is to import modules.

This repository has the https://github.com/Polymer/polymer-resin/blob/master/polymer3-resin.js , but it can't be used because it imports goog.js.

Could you please provide a ES6 module for polymer resin, compatible with Polymer 3?

P.S. As a workaround we assign global Polymer variable ourselves, but it is inconvenient.