Merge pull request #2102 from erik-krogh/deferredModel

JS: add Deferred model in js/use-of-returnless-function

javascript/ql/test/library-tests/TaintTracking/promise.js

@@ -11,4 +11,4 @@ function closure() {
   let resolver = Promise.withResolver();
   resolver.resolve(source());
   sink(resolver.promise); // NOT OK
-}
+}