Make hashCode a getter and not a method.

lib/compiler/implementation/js_backend/native_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.
 
 class NativeEmitter {
 
   CodeEmitterTask emitter;
   CodeBuffer nativeBuffer;
 
   // Classes that participate in dynamic dispatch. These are the
@@ skipping 429 matching lines @@
     emitIsChecks(objectProperties);
 
     // In order to have the toString method on every native class,
     // we must patch the JS Object prototype with a helper method.
     String toStringName = backend.namer.publicInstanceMethodNameByArity(
         const SourceString('toString'), 0);
     objectProperties[toStringName] =
         'function() { return $toStringHelperName(this); }';
 
     // Same as above, but for hashCode.
-    String hashCodeName = backend.namer.publicInstanceMethodNameByArity(
-        const SourceString('hashCode'), 0);
+    String hashCodeName = backend.namer.publicGetterName(
+        const SourceString('hashCode'));
     objectProperties[hashCodeName] =
         'function() { return $hashCodeHelperName(this); }';
 
     // If the native emitter has been asked to take care of the
     // noSuchMethod handlers, we do that now.
     if (handleNoSuchMethod) {
       emitter.emitNoSuchMethodHandlers((String name, CodeBuffer buffer) {
         objectProperties[name] = buffer.toString();
       });
     }
@@ skipping 11 matching lines @@
         if (!first) targetBuffer.add(",\n");
         targetBuffer.add(" $name: $function");
         first = false;
       });
       targetBuffer.add("\n});\n\n");
     }
     targetBuffer.add(nativeBuffer);
     targetBuffer.add('\n');
   }
 }