Fix Kernel tests

pkg/kernel/test/baseline_spec_mode_test.dart

Index: pkg/kernel/test/baseline_spec_mode_test.dart
diff --git a/pkg/kernel/test/baseline_spec_mode_test.dart b/pkg/kernel/test/baseline_spec_mode_test.dart
index f365d78e484c244153ed536ce17bc8bce9710366..c4dda84ec942e578f90458dcd14cfac170c40079 100644
--- a/pkg/kernel/test/baseline_spec_mode_test.dart
+++ b/pkg/kernel/test/baseline_spec_mode_test.dart
@@ -17,10 +17,15 @@ class SpecModeTest extends TestTarget {
   bool get strongMode => false;
 
   @override
-  List<String> transformProgram(Program program) {
+  List<String> performModularTransformations(Program program) {
     new MixinFullResolution().transform(program);
     return const <String>[];
   }
+
+  @override
+  List<String> performGlobalTransformations(Program program) {
+    return const <String>[];
+  }
 }
 
 void main() {