Refactor runtime into libraries, better type reps

test/codegen/expect/sunflower/painter.js

Index: test/codegen/expect/sunflower/painter.js
diff --git a/test/codegen/expect/sunflower/painter.js b/test/codegen/expect/sunflower/painter.js
index 81b9ac1d7864166b85185281f7e7e9330088be28..ad42718ee5e52cc70f969ea6661c2b3ed51c0b87 100644
--- a/test/codegen/expect/sunflower/painter.js
+++ b/test/codegen/expect/sunflower/painter.js
@@ -1,10 +1,12 @@
-dart.library('painter', null, /* Imports */[
+loader.library('painter', null, /* Imports */[
+  "dart/dart_runtime",
+  "dart/dartx",
   'dart/math',
   'dom',
   'dart/core',
   'circle'
 ], /* Lazy imports */[
-], function(exports, math, dom, core, circle) {
+], function(exports, dart, dartx, math, dom, core, circle) {
   'use strict';
   let ORANGE = "orange";
   let RED = "red";