Check for duplicate library names

test/codegen/expect/functions.js

Index: test/codegen/expect/functions.js
diff --git a/test/codegen/expect/functions.js b/test/codegen/expect/functions.js
index 6eb73b2a88e118caa49f38a61b4f8d475beeaf73..cff15fda575e73311907f6123d2c118e8be9f9d6 100644
--- a/test/codegen/expect/functions.js
+++ b/test/codegen/expect/functions.js
@@ -1,6 +1,7 @@
-var functions = dart.defineLibrary(functions, {});
-var core = dart.import(core);
-(function(exports, core) {
+dart.library('functions', null, /* Imports */[
+  'dart/core'
+], /* Lazy imports */[
+], function(exports, core) {
   'use strict';
   function bootstrap() {
     return dart.list([new Foo()], Foo);
@@ -27,4 +28,4 @@ var core = dart.import(core);
   exports.id = id;
   exports.Foo = Foo;
   exports.main = main;
-})(functions, core);
+});