Always initialize top-level `Isolate` for deferred libraries.

sdk/lib/_internal/compiler/implementation/js_emitter/code_emitter_task.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;
 
 const USE_NEW_EMITTER = const bool.fromEnvironment("dart2js.use.new.emitter");
 
 /**
  * Generates the code for all used classes in the program. Static fields (even
@@ skipping 2057 matching lines @@
 
       outputBuffer..write(buildGeneratedBy())
         ..write('${deferredInitializers}.current$_=$_'
                 'function$_(${globalsHolder}) {$N');
       for (String globalObject in Namer.reservedGlobalObjectNames) {
         outputBuffer
             .write('var $globalObject$_=$_'
                    '${globalsHolder}.$globalObject$N');
       }
       outputBuffer
-          .write('var init$_=$_${globalsHolder}.init$N');
+          ..write('var init$_=$_${globalsHolder}.init$N')
+          ..write('var ${namer.isolateName}$_=$_'
+                    '${globalsHolder}.${namer.isolateName}$N');
       if (libraryDescriptorBuffer != null) {
       // TODO(ahe): This defines a lot of properties on the
       // Isolate.prototype object.  We know this will turn it into a
       // slow object in V8, so instead we should do something similar
       // to Isolate.$finishIsolateConstructor.
          outputBuffer
-             ..write('var ${namer.isolateName}$_=$_'
-                     '${globalsHolder}.${namer.isolateName}$N')
-            ..write('var ${namer.currentIsolate}$_=$_$isolatePropertiesName$N')
-            // The classesCollector object ($$).
-            ..write('$classesCollector$_=${_}Object.create(null);$n')
-          ..write('(')
-          ..write(
-              jsAst.prettyPrint(
-                  getReflectionDataParser(classesCollector, backend),
-                  compiler, monitor: compiler.dumpInfoTask))
-          ..write(')')
-          ..write('([$n')
-          ..addBuffer(libraryDescriptorBuffer)
-          ..write('])$N');
+           ..write('var ${namer.currentIsolate}$_=$_$isolatePropertiesName$N')
+           // The classesCollector object ($$).
+           ..write('$classesCollector$_=${_}Object.create(null);$n')
+           ..write('(')
+           ..write(
+               jsAst.prettyPrint(
+                   getReflectionDataParser(classesCollector, backend),
+                   compiler, monitor: compiler.dumpInfoTask))
+           ..write(')')
+           ..write('([$n')
+           ..addBuffer(libraryDescriptorBuffer)
+           ..write('])$N');
 
         if (outputClassLists.containsKey(outputUnit)) {
           outputBuffer.write(
               '$finishClassesName($classesCollector,$_${namer.currentIsolate},'
               '$_$isolatePropertiesName)$N');
         }
 
       }
 
       classesCollector = oldClassesCollector;
@@ skipping 61 matching lines @@
     for (Element element in compiler.enqueuer.codegen.newlyEnqueuedElements) {
       if (element.isInstanceMember) {
         cachedClassBuilders.remove(element.enclosingClass);
 
         nativeEmitter.cachedBuilders.remove(element.enclosingClass);
 
       }
     }
   }
 }