Declarative linking functions run through alternative implementation: 15.2.5.1.1 CreateModuleLinkageRecord not implemented 15.2.5.1.2 LookupExport not implemented 15.2.5.1.3 LookupModuleDependency not implemented 15.2.5.2.1
function createLinkSet(loader, startingLoad) {
      var linkSet = {
        loader: loader,
        loads: [],
        loadingCount: 0
      };
      linkSet.done = new Promise(function(resolve, reject) {
        linkSet.resolve = resolve;
        linkSet.reject = reject;
      });
      addLoadToLinkSet(linkSet, startingLoad);
      return linkSet;
    }