Add --modules=node support

test/codegen/expect/unittest.js

Index: test/codegen/expect/unittest.js
diff --git a/test/codegen/expect/unittest.js b/test/codegen/expect/unittest.js
index 671719272dab6d92c854ba0eec0ada83b81d5c77..dd5d86d81f2e498ff0e07ef16f5ca9e6782bc03a 100644
--- a/test/codegen/expect/unittest.js
+++ b/test/codegen/expect/unittest.js
@@ -8,10 +8,10 @@ dart_library.library('unittest', null, /* Imports */[
   'matcher/src/util',
   'matcher/src/description'
 ], /* Lazy imports */[
-], function(exports, dart, matcher, dom, core, async, interfaces, util, description$) {
+], function(exports, dart, matcher, dom, core, $async, interfaces, util, description$) {
   'use strict';
   let dartx = dart.dartx;
-  dart.export(exports, matcher);
+  dart.export_(exports, matcher);
   function group(name, body) {
     return dart.dsend(dom.window, 'suite', name, body);
   }
@@ -24,7 +24,7 @@ dart_library.library('unittest', null, /* Imports */[
     }
     dart.dsend(dom.window, 'test', name, dart.fn(done => {
       function _finishTest(f) {
-        if (dart.is(f, async.Future)) {
+        if (dart.is(f, $async.Future)) {
           dart.dsend(f, 'then', _finishTest);
         } else {
           dart.dcall(done);