Avoid generating VariableUse nodes with non-identifier names

sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart

Index: sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart b/sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart
index 52284600962a8bf3694d1ff7340d890fe107884c..53c590901abbce7a762663fdb4b0f1fbc2e5af1a 100644
--- a/sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.dart
@@ -39,41 +39,11 @@ class NativeEmitter {
   String get n => emitter.n;
   String get N => emitter.N;
 
-  String get dynamicName {
-    Element element = compiler.findHelper('dynamicFunction');
-    return backend.namer.isolateAccess(element);
-  }
-
-  String get dynamicFunctionTableName {
-    Element element = compiler.findHelper('dynamicFunctionTable');
-    return backend.namer.isolateAccess(element);
-  }
-
-  String get typeNameOfName {
-    Element element = compiler.findHelper('getTypeNameOf');
-    return backend.namer.isolateAccess(element);
-  }
-
   jsAst.Expression get defPropFunction {
     Element element = compiler.findHelper('defineProperty');
     return backend.namer.elementAccess(element);
   }
 
-  String get toStringHelperName {
-    Element element = compiler.findHelper('toStringForNativeObject');
-    return backend.namer.isolateAccess(element);
-  }
-
-  String get hashCodeHelperName {
-    Element element = compiler.findHelper('hashCodeForNativeObject');
-    return backend.namer.isolateAccess(element);
-  }
-
-  String get dispatchPropertyNameVariable {
-    Element element = compiler.findInterceptor('dispatchPropertyName');
-    return backend.namer.isolateAccess(element);
-  }
-
   /**
    * Writes the class definitions for the interceptors to [mainBuffer].
    * Writes code to associate dispatch tags with interceptors to [nativeBuffer].