Implement redirecting constructors.

dart/sdk/lib/_internal/compiler/implementation/resolution/members.dart

Index: dart/sdk/lib/_internal/compiler/implementation/resolution/members.dart
diff --git a/dart/sdk/lib/_internal/compiler/implementation/resolution/members.dart b/dart/sdk/lib/_internal/compiler/implementation/resolution/members.dart
index 357c08ae25077b334580277a1f946c7bc6740d54..719b88b87f79a9823b8c18cd86dd74a6b3dfa481 100644
--- a/dart/sdk/lib/_internal/compiler/implementation/resolution/members.dart
+++ b/dart/sdk/lib/_internal/compiler/implementation/resolution/members.dart
@@ -1875,7 +1875,15 @@ class ResolverVisitor extends CommonResolverVisitor<Element> {
 
   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);
     }