Implement redirecting constructors.

dart/sdk/lib/_internal/compiler/implementation/resolution/members.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 resolution;
 
 abstract class TreeElements {
   Element operator[](Node node);
   Selector getSelector(Send send);
   DartType getType(Node node);
@@ skipping 1857 matching lines @@
       visit(link.head);
     }
   }
 
   visitOperator(Operator node) {
     unimplemented(node, 'operator');
   }
 
   visitReturn(Return node) {
     if (node.isRedirectingFactoryBody) {
-      useElement(node.expression, resolveRedirectingFactory(node));
+      Element redirectionTarget = resolveRedirectingFactory(node);
+      useElement(node.expression, redirectionTarget);
+      assert(invariant(node, enclosingElement.isFactoryConstructor()));
+      FunctionElement constructor = enclosingElement;
+      // TODO(ahe): Check that this doesn't lead to a cycle.  For now,
+      // that is checked on demand when the backend requests this
+      // constructor and it leads to a crash.
+      constructor.defaultImplementation = redirectionTarget;
+      world.registerStaticUse(redirectionTarget);
     } else {
       visit(node.expression);
     }
   }
 
   visitThrow(Throw node) {
     if (!inCatchBlock && node.expression == null) {
       error(node, MessageKind.THROW_WITHOUT_EXPRESSION);
     }
     visit(node.expression);
@@ skipping 1149 matching lines @@
     return e;
   }
 
   /// Assumed to be called by [resolveRedirectingFactory].
   Element visitReturn(Return node) {
     Node expression = node.expression;
     return finishConstructorReference(visit(expression),
                                       expression, expression);
   }
 }