Make an erroneous element when setting a final field.

sdk/lib/_internal/compiler/implementation/ssa/builder.dart

 // Copyright (c) 2012, 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 ssa;
 
 /**
  * A special element for the extra parameter taken by intercepted
  * methods. We need to override [Element.computeType] because our
  * optimizers may look at its declared type.
@@ skipping 3574 matching lines @@
   visitSendSet(SendSet node) {
     Element element = elements[node];
     if (!Elements.isUnresolved(element) && element.impliesType()) {
       Identifier selector = node.selector;
       generateThrowNoSuchMethod(node, selector.source.slowToString(),
                                 argumentNodes: node.arguments);
       return;
     }
     Operator op = node.assignmentOperator;
     if (node.isSuperCall) {
-      if (element == null) return generateSuperNoSuchMethodSend(node);
+      if (Elements.isUnresolved(element)) {
+        return generateSuperNoSuchMethodSend(node);
+      }
       HInstruction target = new HStatic(element);
       HInstruction context = localsHandler.readThis();
       add(target);
       var inputs = <HInstruction>[target, context];
       addDynamicSendArgumentsToList(node, inputs);
       if (!identical(node.assignmentOperator.source.stringValue, '=')) {
         compiler.unimplemented('complex super assignment',
                                node: node.assignmentOperator);
       }
       push(new HInvokeSuper(inputs, isSetter: true));
@@ skipping 1486 matching lines @@
           new HSubGraphBlockInformation(elseBranch.graph));
 
     HBasicBlock conditionStartBlock = conditionBranch.block;
     conditionStartBlock.setBlockFlow(info, joinBlock);
     SubGraph conditionGraph = conditionBranch.graph;
     HIf branch = conditionGraph.end.last;
     assert(branch is HIf);
     branch.blockInformation = conditionStartBlock.blockFlow;
   }
 }