Add support for super aliases to new emitter.

pkg/compiler/lib/src/js_emitter/old_emitter/container_builder.dart

Index: pkg/compiler/lib/src/js_emitter/old_emitter/container_builder.dart
diff --git a/pkg/compiler/lib/src/js_emitter/old_emitter/container_builder.dart b/pkg/compiler/lib/src/js_emitter/old_emitter/container_builder.dart
index 573a9ee662cbdfb5725cd66bb22d8f5a13d54d69..569114979094d4c976b8c77be86c46ee0a3be7e9 100644
--- a/pkg/compiler/lib/src/js_emitter/old_emitter/container_builder.dart
+++ b/pkg/compiler/lib/src/js_emitter/old_emitter/container_builder.dart
@@ -285,7 +285,8 @@ class ContainerBuilder extends CodeEmitterHelper {
     final bool canBeReflected = method.canBeReflected;
     final bool canBeApplied = method.canBeApplied;
     final bool isClosure = method is InstanceMethod && method.isClosure;
-    final bool hasSuperAlias = method is InstanceMethod && method.hasSuperAlias;
+    final bool hasSuperAlias = method is InstanceMethod &&
+        method.superAlias != null;
 
     final bool needStructuredInfo =
         canTearOff || canBeReflected || canBeApplied || hasSuperAlias;