Improve checking of patches.

sdk/lib/_internal/compiler/implementation/lib/isolate_patch.dart

Index: sdk/lib/_internal/compiler/implementation/lib/isolate_patch.dart
diff --git a/sdk/lib/_internal/compiler/implementation/lib/isolate_patch.dart b/sdk/lib/_internal/compiler/implementation/lib/isolate_patch.dart
index a8d3c27bd3bfb58cb1c31aac44b373909f8f3614..aab847a4dc3a3579b582c2270be9cfc3e17adc1c 100644
--- a/sdk/lib/_internal/compiler/implementation/lib/isolate_patch.dart
+++ b/sdk/lib/_internal/compiler/implementation/lib/isolate_patch.dart
@@ -9,19 +9,19 @@ import 'dart:_isolate_helper' show IsolateNatives,
                                    ReceivePortImpl;
 
 patch class _Isolate {
-  patch ReceivePort get port {
+  patch static ReceivePort get port {
     if (lazyPort == null) {
       lazyPort = new ReceivePort();
     }
     return lazyPort;
   }
 
-  patch SendPort spawnFunction(void topLevelFunction(),
+  patch static SendPort spawnFunction(void topLevelFunction(),
       [bool UnhandledExceptionCallback(IsolateUnhandledException e)]) {
     return IsolateNatives.spawnFunction(topLevelFunction);
   }
 
-  patch SendPort spawnUri(String uri) {
+  patch static SendPort spawnUri(String uri) {
     return IsolateNatives.spawn(null, uri, false);
   }
 }