Fix the loops break label test with Kernel.

tests/compiler/dart2js/kernel/loops_test.dart

Index: tests/compiler/dart2js/kernel/loops_test.dart
diff --git a/tests/compiler/dart2js/kernel/loops_test.dart b/tests/compiler/dart2js/kernel/loops_test.dart
index 42ff8541726169ef073f50c47a690888547a646e..13a75e759e82f50e6ae6d5a719e7ee500c2c631b 100644
--- a/tests/compiler/dart2js/kernel/loops_test.dart
+++ b/tests/compiler/dart2js/kernel/loops_test.dart
@@ -83,9 +83,7 @@ main() {
     return check(code, disableTypeInference: false);
   });
 
-  // TODO(efortuna): Fix and uncomment.
-  // See bug https://github.com/dart-lang/sdk/issues/28670
-  /*test('for loop with break to label', () {
+  test('for loop with break to label', () {
     String code = '''
 var a = 0;
 main() {
@@ -100,5 +98,5 @@ main() {
   return sum;
 }''';
     return check(code, disableTypeInference: false);
-  });*/
+  });
 }