Move towards using WorldImpact for codegen

pkg/compiler/lib/src/js_emitter/native_emitter.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart2js.js_emitter;
 
 class NativeEmitter {
   // TODO(floitsch): the native-emitter should not know about ClassBuilders.
   final Map<Element, full_js_emitter.ClassBuilder> cachedBuilders;
 
@@ skipping 173 matching lines @@
         cls.nativeLeafTags = leafTags[cls].toList(growable: false);
       }
       if (nonleafTags[cls] != null) {
         cls.nativeNonLeafTags = nonleafTags[cls].toList(growable: false);
       }
       cls.nativeExtensions = extensionPoints[cls];
     }
 
     // Add properties containing the information needed to construct maps used
     // by getNativeInterceptor and custom elements.
-    if (compiler.enqueuer.codegen.nativeEnqueuer
-        .hasInstantiatedNativeClasses()) {
+    if (compiler.enqueuer.codegen.nativeEnqueuer.hasInstantiatedNativeClasses) {
       fillNativeInfo(jsInterceptorClass);
       for (Class cls in classes) {
         if (!cls.isNative || neededClasses.contains(cls)) {
           fillNativeInfo(cls);
         }
       }
     }
 
     // TODO(sra): Issue #13731- this is commented out as part of custom
     // element constructor work.
@@ skipping 145 matching lines @@
     // used.  We should also use an interceptor if the check can't be satisfied
     // by a native class in case we get a native instance that tries to spoof
     // the type info.  i.e the criteria for whether or not to use an interceptor
     // is whether the receiver can be native, not the type of the test.
     if (element == null || !element.isClass) return false;
     ClassElement cls = element;
     if (backend.isNativeOrExtendsNative(cls)) return true;
     return isSupertypeOfNativeClass(element);
   }
 }