Encode super calls via extra properties on prototypes.

pkg/dart2js_incremental/lib/library_updater.dart

Index: pkg/dart2js_incremental/lib/library_updater.dart
diff --git a/pkg/dart2js_incremental/lib/library_updater.dart b/pkg/dart2js_incremental/lib/library_updater.dart
index cc29d1b9c3c7157947f2dba25035bad48e86f2fa..848ad84381de37e0fe7659e30cbd4717268e6fb4 100644
--- a/pkg/dart2js_incremental/lib/library_updater.dart
+++ b/pkg/dart2js_incremental/lib/library_updater.dart
@@ -606,12 +606,11 @@ class LibraryUpdater extends JsFeatures {
       statements.add(
           js.statement('#.prototype.# = f', [elementAccess, name]));
 
-      // TODO(ahe): Restore when isAliasedSuperMember is restored.
-      // if (backend.isAliasedSuperMember(element)) {
-      //   String superName = namer.getNameOfAliasedSuperMember(element);
-      //   statements.add(
-      //       js.statement('#.prototype.# = f', [elementAccess, superName]));
-      // }
+      if (backend.isAliasedSuperMember(element)) {
+        String superName = namer.getNameOfAliasedSuperMember(element);
+        statements.add(
+          js.statement('#.prototype.# = f', [elementAccess, superName]));
+      }
     } else {
       jsAst.Node elementAccess = namer.elementAccess(element);
       jsAst.Expression globalFunctionsAccess =
@@ -791,10 +790,9 @@ class RemovedFunctionUpdate extends RemovalUpdate
     if (element.isInstanceMember) {
       elementAccess = namer.elementAccess(element.enclosingClass);
       name = namer.getNameOfMember(element);
-      // TODO(ahe): Restore when isAliasedSuperMember is restored.
-      // if (backend.isAliasedSuperMember(element)) {
-      //   superName = namer.getNameOfAliasedSuperMember(element);
-      // }
+      if (backend.isAliasedSuperMember(element)) {
+        superName = namer.getNameOfAliasedSuperMember(element);
+      }
     } else {
       elementAccess = namer.elementAccess(element);
     }