Check for duplicate library names

lib/runtime/dart/_native_typed_data.js

Index: lib/runtime/dart/_native_typed_data.js
diff --git a/lib/runtime/dart/_native_typed_data.js b/lib/runtime/dart/_native_typed_data.js
index a19494a97e032d867d37feaa9b33a0c681100701..78dd452f69e76b9d4d6fbf457605ecef59f14af8 100644
--- a/lib/runtime/dart/_native_typed_data.js
+++ b/lib/runtime/dart/_native_typed_data.js
@@ -1,11 +1,11 @@
-var _native_typed_data = dart.defineLibrary(_native_typed_data, {});
-var core = dart.import(core);
-var typed_data = dart.import(typed_data);
-var collection = dart.import(collection);
-var _internal = dart.import(_internal);
-var _interceptors = dart.lazyImport(_interceptors);
-var _js_helper = dart.lazyImport(_js_helper);
-var math = dart.import(math);
+dart.defineLibrary('_native_typed_data');
+dart.import('core');
+dart.import('typed_data');
+dart.import('collection');
+dart.import('_internal');
+dart.lazyImport('_interceptors');
+dart.lazyImport('_js_helper');
+dart.import('math');
 (function(exports, core, typed_data, collection, _internal, _interceptors, _js_helper, math) {
   'use strict';
   class NativeByteBuffer extends core.Object {