Fix ddc build_sdk step

pkg/dev_compiler/lib/js/es6/dart_sdk.js

Index: pkg/dev_compiler/lib/js/es6/dart_sdk.js
diff --git a/pkg/dev_compiler/lib/js/es6/dart_sdk.js b/pkg/dev_compiler/lib/js/es6/dart_sdk.js
index 55535a0670ace228f6ee9b21a397ba84c64f49dc..bda3f04cce7ab9094fdd66ed71fb4b0d6faa1045 100644
--- a/pkg/dev_compiler/lib/js/es6/dart_sdk.js
+++ b/pkg/dev_compiler/lib/js/es6/dart_sdk.js
@@ -116240,6 +116240,22 @@ dart.setSignature(web_sql.SqlTransaction, {
   methods: () => ({[$executeSql]: dart.fnType(dart.void, [core.String], [core.List, web_sql.SqlStatementCallback, web_sql.SqlStatementErrorCallback])})
 });
 dart.registerExtension("SQLTransaction", web_sql.SqlTransaction);
+nativewrappers.NativeFieldWrapperClass1 = class NativeFieldWrapperClass1 extends core.Object {};
+(nativewrappers.NativeFieldWrapperClass1.new = function() {
+}).prototype = nativewrappers.NativeFieldWrapperClass1.prototype;
+dart.addTypeTests(nativewrappers.NativeFieldWrapperClass1);
+nativewrappers.NativeFieldWrapperClass2 = class NativeFieldWrapperClass2 extends core.Object {};
+(nativewrappers.NativeFieldWrapperClass2.new = function() {
+}).prototype = nativewrappers.NativeFieldWrapperClass2.prototype;
+dart.addTypeTests(nativewrappers.NativeFieldWrapperClass2);
+nativewrappers.NativeFieldWrapperClass3 = class NativeFieldWrapperClass3 extends core.Object {};
+(nativewrappers.NativeFieldWrapperClass3.new = function() {
+}).prototype = nativewrappers.NativeFieldWrapperClass3.prototype;
+dart.addTypeTests(nativewrappers.NativeFieldWrapperClass3);
+nativewrappers.NativeFieldWrapperClass4 = class NativeFieldWrapperClass4 extends core.Object {};
+(nativewrappers.NativeFieldWrapperClass4.new = function() {
+}).prototype = nativewrappers.NativeFieldWrapperClass4.prototype;
+dart.addTypeTests(nativewrappers.NativeFieldWrapperClass4);
 dart.trackLibraries("dart_sdk", {
   "dart:_runtime": dart,
   "dart:_debugger": _debugger,