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

lib/runtime/dart/async.js

Index: lib/runtime/dart/async.js
diff --git a/lib/runtime/dart/async.js b/lib/runtime/dart/async.js
index 1a903cf608c52099f578034ad25c200bb009cedd..d09264f34cb5d13a74b29dc1987b685ad5dd8466 100644
--- a/lib/runtime/dart/async.js
+++ b/lib/runtime/dart/async.js
@@ -20,8 +20,8 @@ var async;
   let _getBestStackTrace = Symbol('_getBestStackTrace');
   class AsyncError extends core.Object {
     AsyncError(error, stackTrace) {
-      this.error = error;
-      this.stackTrace = stackTrace;
+      dart.initField(AsyncError, this, 'error', error);
+      dart.initField(AsyncError, this, 'stackTrace', stackTrace);
     }
     toString() {
       return this.error.toString();
@@ -850,9 +850,9 @@ var async;
   let _recordCancel = Symbol('_recordCancel');
   let _recordPause = Symbol('_recordPause');
   let _recordResume = Symbol('_recordResume');
+  let _STATE_CANCEL_ON_ERROR = Symbol('_STATE_CANCEL_ON_ERROR');
   let _zone = Symbol('_zone');
   let _state = Symbol('_state');
-  let _STATE_CANCEL_ON_ERROR = Symbol('_STATE_CANCEL_ON_ERROR');
   let _onData = Symbol('_onData');
   let _onError = Symbol('_onError');
   let _onDone = Symbol('_onDone');
@@ -1654,8 +1654,8 @@ var async;
   class DeferredLibrary extends core.Object {
     DeferredLibrary(libraryName, opts) {
       let uri = opts && 'uri' in opts ? opts.uri : null;
-      this.libraryName = libraryName;
-      this.uri = uri;
+      dart.initField(DeferredLibrary, this, 'libraryName', libraryName);
+      dart.initField(DeferredLibrary, this, 'uri', uri);
     }
     load() {
       throw 'DeferredLibrary not supported. ' + 'please use the `import "lib.dart" deferred as lib` syntax.';
@@ -1664,7 +1664,7 @@ var async;
   let _s = Symbol('_s');
   class DeferredLoadException extends core.Object {
     DeferredLoadException(s) {
-      this[_s] = s;
+      dart.initField(DeferredLoadException, this, _s, s);
     }
     toString() {
       return `DeferredLoadException: '${this[_s]}'`;
@@ -1842,8 +1842,8 @@ var async;
     TimeoutException(message, duration) {
       if (duration === void 0)
         duration = null;
-      this.message = message;
-      this.duration = duration;
+      dart.initField(TimeoutException, this, 'message', message);
+      dart.initField(TimeoutException, this, 'duration', duration);
     }
     toString() {
       let result = "TimeoutException";
@@ -3562,9 +3562,9 @@ var async;
     return _BroadcastSubscriptionWrapper;
   });
   let _BroadcastSubscriptionWrapper = _BroadcastSubscriptionWrapper$();
+  let _STATE_FOUND = Symbol('_STATE_FOUND');
   let _current = Symbol('_current');
   let _futureOrPrefetch = Symbol('_futureOrPrefetch');
-  let _STATE_FOUND = Symbol('_STATE_FOUND');
   let _STATE_DONE = Symbol('_STATE_DONE');
   let _STATE_MOVING = Symbol('_STATE_MOVING');
   let _STATE_EXTRA_DATA = Symbol('_STATE_EXTRA_DATA');