Generative constructors in the new dart backend.

pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart

Index: pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart
index d7ec6a950c08a2c129ea352e784b1b2ed492cc72..7ae78a15f1a4cfb903b4707beb99bd161f86429f 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart
@@ -40,7 +40,7 @@ class SExpressionStringifier extends Visitor<String> with Indentation {
 
   String visitFunctionDefinition(FunctionDefinition node) {
     String name = node.element.name;
-    namer.useReturnName(node.returnContinuation);
+    namer.useReturnName(node.body.returnContinuation);
     String closureVariables = node.closureVariables.isEmpty
         ? ''
         : '{${node.closureVariables.map(namer.defineClosureName).join(' ')}} ';
@@ -53,7 +53,7 @@ class SExpressionStringifier extends Visitor<String> with Indentation {
   String visitFieldDefinition(FieldDefinition node) {
     String name = node.element.name;
     if (node.hasInitializer) {
-      namer.useReturnName(node.returnContinuation);
+      namer.useReturnName(node.body.returnContinuation);
       String body = indentBlock(() => visit(node.body));
       return '$indentation(FieldDefinition $name (return)\n'
              '$body)';