fixes #43, remove => workaround

lib/runtime/dart/isolate.js

 var isolate = dart.defineLibrary(isolate, {});
 var core = dart.import(core);
 var _isolate_helper = dart.lazyImport(_isolate_helper);
 var async = dart.import(async);
 (function(exports, core, _isolate_helper, async) {
   'use strict';
   class Capability extends core.Object {
     static new() {
       return new _isolate_helper.CapabilityImpl();
     }
@@ skipping 126 matching lines @@
     get errors() {
       let controller = null;
       let port = null;
       let handleError = message => {
         let errorDescription = dart.as(dart.dindex(message, 0), core.String);
         let stackDescription = dart.as(dart.dindex(message, 1), core.String);
         let error = new RemoteError(errorDescription, stackDescription);
         controller.addError(error, error.stackTrace);
       };
       dart.fn(handleError, dart.void, [core.Object]);
-      controller = async.StreamController.broadcast({sync: true, onListen: dart.fn((() => {
+      controller = async.StreamController.broadcast({sync: true, onListen: dart.fn(() => {
           port = RawReceivePort.new(handleError);
           this.addErrorListener(port.sendPort);
-        }).bind(this)), onCancel: dart.fn((() => {
+        }), onCancel: dart.fn(() => {
           this.removeErrorListener(port.sendPort);
           port.close();
           port = null;
-        }).bind(this))});
+        })});
       return controller.stream;
     }
   }
   dart.setSignature(Isolate, {
     constructors: () => ({Isolate: [Isolate, [SendPort], {pauseCapability: Capability, terminateCapability: Capability}]}),
     methods: () => ({
       pause: [Capability, [], [Capability]],
       [_pause]: [dart.void, [Capability]],
       resume: [dart.void, [Capability]],
       addOnExitListener: [dart.void, [SendPort]],
@@ skipping 88 matching lines @@
   });
   // Exports:
   exports.Capability = Capability;
   exports.IsolateSpawnException = IsolateSpawnException;
   exports.Isolate = Isolate;
   exports.SendPort = SendPort;
   exports.ReceivePort = ReceivePort;
   exports.RawReceivePort = RawReceivePort;
   exports.RemoteError = RemoteError;
 })(isolate, core, _isolate_helper, async);