Implement redirecting constructors.

dart/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;
 
 class Interceptors {
   Compiler compiler;
   Interceptors(Compiler this.compiler);
 
@@ skipping 3047 matching lines @@
         return HType.UNKNOWN;
       }
     }
 
     Element constructor = elements[node];
     Selector selector = elements.getSelector(node);
     if (compiler.enqueuer.resolution.getCachedElements(constructor) == null) {
       compiler.internalError("Unresolved element: $constructor", node: node);
     }
     FunctionElement functionElement = constructor;
-    constructor = functionElement.defaultImplementation;
+    constructor = functionElement.redirectionTarget;
     // TODO(5346): Try to avoid the need for calling [declaration] before
     // creating an [HStatic].
     HInstruction target = new HStatic(constructor.declaration);
     add(target);
     var inputs = <HInstruction>[];
     inputs.add(target);
     // TODO(5347): Try to avoid the need for calling [implementation] before
     // calling [addStaticSendArgumentsToList].
     bool succeeded = addStaticSendArgumentsToList(selector, node.arguments,
                                                   constructor.implementation,
@@ skipping 1684 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;
   }
 }