Encode super calls via extra properties on prototypes.

sdk/lib/_internal/compiler/implementation/js_backend/namer.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of js_backend;
 
 /**
  * Assigns JavaScript identifiers to Dart variables, class-names and members.
  */
 class Namer implements ClosureNamer {
@@ skipping 202 matching lines @@
       // 26 letters in the alphabet, 25 not counting I.
       assert(reservedGlobalObjectNames.length == 25);
       _jsVariableReserved.addAll(reservedGlobalHelperFunctions);
     }
     return _jsVariableReserved;
   }
 
   final String currentIsolate = r'$';
   final String getterPrefix = r'get$';
   final String setterPrefix = r'set$';
+  final String superPrefix = r'super$';
   final String metadataField = '@';
   final String callPrefix = 'call';
   final String callCatchAllName = r'call$catchAll';
   final String reflectableField = r'$reflectable';
   final String defaultValuesField = r'$defaultValues';
   final String methodsWithOptionalArgumentsField =
       r'$methodsWithOptionalArguments';
 
   final String classDescriptorProperty = r'^';
 
@@ skipping 569 matching lines @@
 
   String getNameOfLibrary(LibraryElement library) => getNameX(library);
 
   String getNameOfClass(ClassElement cls) => getNameX(cls);
 
   String getNameOfField(VariableElement field) => getNameX(field);
 
   // TODO(ahe): Remove this method. Use get getNameOfMember instead.
   String getNameOfInstanceMember(Element member) => getNameX(member);
 
+  String getNameOfAliasedSuperMember(Element member) {
+    ClassElement superClass = member.enclosingClass;
+    String className = getNameOfClass(superClass);
+    String memberName = getNameOfMember(member);
+    String proposal = "$superPrefix$className\$$memberName";
+    return getMappedInstanceName(proposal);
+  }
+
   String getNameOfMember(Element member) => getNameX(member);
 
   String getNameOfGlobalField(VariableElement field) => getNameX(field);
 
   /// Returns true if [element] is stored on current isolate ('$').  We intend
   /// to store only mutable static state in [currentIsolate], constants are
   /// stored in 'C', and functions, accessors, classes, etc. are stored in one
   /// of the other objects in [reservedGlobalObjectNames].
   bool isPropertyOfCurrentIsolate(Element element) {
     // TODO(ahe): Make sure this method's documentation is always true and
@@ skipping 565 matching lines @@
         if (!first) {
           sb.write('_');
         }
         sb.write('_');
         visit(parameter);
         first = true;
       }
     }
   }
 }