Use signature inheritance when method types are unchanged

lib/runtime/dart/_isolate_helper.js

 var _isolate_helper = dart.defineLibrary(_isolate_helper, {});
 var core = dart.import(core);
 var _native_typed_data = dart.import(_native_typed_data);
 var _interceptors = dart.lazyImport(_interceptors);
 var _js_helper = dart.lazyImport(_js_helper);
 var isolate = dart.import(isolate);
 var _foreign_helper = dart.import(_foreign_helper);
 var _js_embedded_names = dart.import(_js_embedded_names);
 var collection = dart.import(collection);
 var async = dart.import(async);
@@ skipping 1269 matching lines @@
     }
     ['=='](other) {
       return dart.is(other, _NativeJsSendPort) && dart.notNull(dart.equals(this[_receivePort], dart.dload(other, _receivePort)));
     }
     get hashCode() {
       return this[_receivePort][_id];
     }
   }
   _NativeJsSendPort[dart.implements] = () => [isolate.SendPort];
   dart.setSignature(_NativeJsSendPort, {
-    methods: () => ({
-      send: dart.functionType(dart.void, [dart.dynamic]),
-      '==': dart.functionType(core.bool, [dart.dynamic])
-    })
+    methods: () => ({send: dart.functionType(dart.void, [dart.dynamic])})
   });
   class _WorkerSendPort extends _BaseSendPort {
     _WorkerSendPort(workerId, isolateId, receivePortId) {
       this[_workerId] = workerId;
       this[_receivePortId] = receivePortId;
       super._BaseSendPort(isolateId);
     }
     send(message) {
       let workerMessage = _serializeMessage(dart.map({command: 'message', port: this, msg: message}));
       if (exports._globalState.isWorker) {
         exports._globalState.mainManager.postMessage(workerMessage);
       } else {
         let manager = exports._globalState.managers.get(this[_workerId]);
         if (manager != null) {
           manager.postMessage(workerMessage);
         }
       }
     }
     ['=='](other) {
       return dart.is(other, _WorkerSendPort) && dart.equals(this[_workerId], dart.dload(other, _workerId)) && dart.equals(this[_isolateId], dart.dload(other, _isolateId)) && dart.equals(this[_receivePortId], dart.dload(other, _receivePortId));
     }
     get hashCode() {
       return dart.notNull(this[_workerId]) << 16 ^ dart.notNull(this[_isolateId]) << 8 ^ dart.notNull(this[_receivePortId]);
     }
   }
   _WorkerSendPort[dart.implements] = () => [isolate.SendPort];
   dart.setSignature(_WorkerSendPort, {
-    methods: () => ({
-      send: dart.functionType(dart.void, [dart.dynamic]),
-      '==': dart.functionType(core.bool, [dart.dynamic])
-    })
+    methods: () => ({send: dart.functionType(dart.void, [dart.dynamic])})
   });
   let _handler = Symbol('_handler');
   class RawReceivePortImpl extends core.Object {
     RawReceivePortImpl(handler) {
       this[_handler] = handler;
       this[_id] = (() => {
         let x = RawReceivePortImpl._nextFreeId;
         RawReceivePortImpl._nextFreeId = dart.notNull(x) + 1;
         return x;
       })();
@@ skipping 201 matching lines @@
   exports.leaveJsAsync = leaveJsAsync;
   exports.isWorker = isWorker;
   exports.startRootIsolate = startRootIsolate;
   exports.IsolateNatives = IsolateNatives;
   exports.RawReceivePortImpl = RawReceivePortImpl;
   exports.ReceivePortImpl = ReceivePortImpl;
   exports.TimerImpl = TimerImpl;
   exports.hasTimer = hasTimer;
   exports.CapabilityImpl = CapabilityImpl;
 })(_isolate_helper, core, _native_typed_data, _interceptors, _js_helper, isolate, _foreign_helper, _js_embedded_names, collection, async);