isolate: fix how we get the current script now that frog automatically wraps the

lib/compiler/implementation/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.
 
 /**
  * A function element that represents a closure call. The signature is copied
  * from the given element.
  */
 class ClosureInvocationElement extends FunctionElement {
   ClosureInvocationElement(SourceString name,
@@ skipping 658 matching lines @@
       mainEnsureGetter = "$mainAccess.$invocationName = $mainAccess";
     }
 
     // TODO(ngeoffray): These globals are currently required by the isolate
     // library, but since leg already generates code on an Isolate object, they
     // are not really needed. We should remove them once Leg replaces Frog.
     buffer.add("""
 var \$globalThis = $currentIsolate;
 var \$globalState;
 var \$globals;
+var \$isWorker;
+var \$supportsWorkers;
+var \$thisScriptUrl;
 function \$static_init(){};
 
 function \$initGlobals(context) {
   context.isolateStatics = new ${namer.ISOLATE}();
 }
 function \$setGlobals(context) {
   $currentIsolate = context.isolateStatics;
   \$globalThis = $currentIsolate;
 }
 $mainEnsureGetter
@@ skipping 37 matching lines @@
       nativeEmitter.emitDynamicDispatchMetadata();
       mainBuffer.add(
           'var ${namer.CURRENT_ISOLATE} = new ${namer.ISOLATE}();\n');
       nativeEmitter.assembleCode(mainBuffer);
       emitMain(mainBuffer);
       compiler.assembledCode = mainBuffer.toString();
     });
     return compiler.assembledCode;
   }
 }