Only emit support for aliasing methods if super calls are present.

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

Index: pkg/compiler/lib/src/js_emitter/old_emitter/emitter.dart
diff --git a/pkg/compiler/lib/src/js_emitter/old_emitter/emitter.dart b/pkg/compiler/lib/src/js_emitter/old_emitter/emitter.dart
index 0ea1989c086d203fba248ef852890c3e388e6e12..91d8ff4647a2ce72f195947a87cfa4e8e811fff6 100644
--- a/pkg/compiler/lib/src/js_emitter/old_emitter/emitter.dart
+++ b/pkg/compiler/lib/src/js_emitter/old_emitter/emitter.dart
@@ -355,6 +355,7 @@ class OldEmitter implements Emitter {
   }
 
   List buildSplitOffAliases() {
+    if (backend.aliasedSuperMembers.isEmpty) return [];
     return [js(r'''
         var splitOffAliases = function(constructor) {
           var hasOwnProperty = Object.prototype.hasOwnProperty;
@@ -543,7 +544,7 @@ class OldEmitter implements Emitter {
 
         // Process aliased members due to super calls. We have to do this early
         // to ensure that we also hit the object class.
-        splitOffAliases(constructor);
+        if (#) splitOffAliases(constructor);
 
         // The superclass is only false (empty string) for the Dart Object
         // class.  The minifier together with noSuchMethod can put methods on
@@ -609,6 +610,7 @@ class OldEmitter implements Emitter {
         }
       }
     }''', [finishedClassesAccess,
+           backend.aliasedSuperMembers.isNotEmpty,
            !nativeClasses.isEmpty,
            interceptorsByTagAccess,
            leafTagsAccess,