Fix ForwardingConstructorElementZ.computeEffectiveTargetType

pkg/compiler/lib/src/serialization/modelz.dart

 // Copyright (c) 2015, 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.
 
 /// Implementation of the element model used for deserialiation.
 ///
 /// These classes are created by [ElementDeserializer] triggered by the
 /// [Deserializer].
 
 library dart2js.serialization.modelz;
@@ skipping 1238 matching lines @@
   @override
   accept(ElementVisitor visitor, arg) {
     return visitor.visitConstructorElement(this, arg);
   }
 
   @override
   AsyncMarker get asyncMarker => AsyncMarker.SYNC;
 
   @override
   InterfaceType computeEffectiveTargetType(InterfaceType newType) {
-    return enclosingClass.thisType;
+    return enclosingClass.thisType.substByContext(newType);
   }
 
   @override
   DartType computeType(Resolution resolution) => type;
 
   @override
   bool get isConst => false;
 
   @override
   ConstantConstructor get constantConstructor => null;
@@ skipping 851 matching lines @@
   }
 
   @override
   ElementKind get kind => ElementKind.PREFIX;
 
   @override
   Element lookupLocalMember(String memberName) {
     return _unsupported('lookupLocalMember');
   }
 }