fixes #52, fields shadowing getters/setters or other fields

lib/runtime/dart/_isolate_helper.js

Index: lib/runtime/dart/_isolate_helper.js
diff --git a/lib/runtime/dart/_isolate_helper.js b/lib/runtime/dart/_isolate_helper.js
index 0fdbdfe3bf62ca387f590aa292c21f658ce81809..830c7b2558e967b06e2485b18deda665edf631fd 100644
--- a/lib/runtime/dart/_isolate_helper.js
+++ b/lib/runtime/dart/_isolate_helper.js
@@ -1196,33 +1196,33 @@ var _isolate_helper;
     }
   }
   _WorkerSendPort[dart.implements] = () => [isolate.SendPort];
-  let _handler = Symbol('_handler');
   let _nextFreeId = Symbol('_nextFreeId');
+  let _handler = Symbol('_handler');
   class RawReceivePortImpl extends core.Object {
     RawReceivePortImpl(handler) {
-      this[_handler] = handler;
-      this[_id] = (() => {
+      dart.initField(RawReceivePortImpl, this, _handler, handler);
+      dart.initField(RawReceivePortImpl, this, _id, (() => {
         let x = RawReceivePortImpl[_nextFreeId];
         RawReceivePortImpl[_nextFreeId] = dart.notNull(x) + 1;
         return x;
-      })();
-      this[_isClosed] = false;
+      })());
+      dart.initField(RawReceivePortImpl, this, _isClosed, false);
       exports._globalState.currentContext.register(this[_id], this);
     }
     weak(handler) {
-      this[_handler] = handler;
-      this[_id] = (() => {
+      dart.initField(RawReceivePortImpl, this, _handler, handler);
+      dart.initField(RawReceivePortImpl, this, _id, (() => {
         let x = RawReceivePortImpl[_nextFreeId];
         RawReceivePortImpl[_nextFreeId] = dart.notNull(x) + 1;
         return x;
-      })();
-      this[_isClosed] = false;
+      })());
+      dart.initField(RawReceivePortImpl, this, _isClosed, false);
       exports._globalState.currentContext.registerWeak(this[_id], this);
     }
     [_controlPort]() {
-      this[_handler] = null;
-      this[_id] = 0;
-      this[_isClosed] = false;
+      dart.initField(RawReceivePortImpl, this, _handler, null);
+      dart.initField(RawReceivePortImpl, this, _id, 0);
+      dart.initField(RawReceivePortImpl, this, _isClosed, false);
     }
     set handler(newHandler) {
       this[_handler] = newHandler;
@@ -1289,9 +1289,9 @@ var _isolate_helper;
   let _handle = Symbol('_handle');
   class TimerImpl extends core.Object {
     TimerImpl(milliseconds, callback) {
-      this[_once] = true;
-      this[_inEventLoop] = false;
-      this[_handle] = null;
+      dart.initField(TimerImpl, this, _once, true);
+      dart.initField(TimerImpl, this, _inEventLoop, false);
+      dart.initField(TimerImpl, this, _handle, null);
       if (milliseconds == 0 && (!dart.notNull(hasTimer()) || dart.notNull(exports._globalState.isWorker))) {
         // Function internalCallback: () → void
         function internalCallback() {
@@ -1316,9 +1316,9 @@ var _isolate_helper;
       }
     }
     periodic(milliseconds, callback) {
-      this[_once] = false;
-      this[_inEventLoop] = false;
-      this[_handle] = null;
+      dart.initField(TimerImpl, this, _once, false);
+      dart.initField(TimerImpl, this, _inEventLoop, false);
+      dart.initField(TimerImpl, this, _handle, null);
       if (hasTimer()) {
         enterJsAsync();
         this[_handle] = self.setInterval(_js_helper.convertDartClosureToJS((() => {
@@ -1363,7 +1363,7 @@ var _isolate_helper;
       this[_internal](_js_helper.random64());
     }
     [_internal](id) {
-      this[_id] = id;
+      dart.initField(CapabilityImpl, this, _id, id);
     }
     get hashCode() {
       let hash = this[_id];