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 177d61148bf0aa4ac35ef6cb7461fe6dc1ff2ea2..14adf79f0be35d8018a3f82b784c7be5f446c7c9 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
@@ -46,12 +46,12 @@ 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
         ? ''
         : '{${node.closureVariables.map(namer.defineClosureName).join(' ')}} ';
     String parameters = node.parameters.map(visit).join(' ');
-    String body = indentBlock(() => visit(node.body));
+    String body = indentBlock(() => visit(node.body.body));
     return '$indentation(FunctionDefinition $name $closureVariables'
            '($parameters return)\n$body)';
   }
@@ -59,8 +59,8 @@ class SExpressionStringifier extends Visitor<String> with Indentation {
   String visitFieldDefinition(FieldDefinition node) {
     String name = node.element.name;
     if (node.hasInitializer) {
-      namer.useReturnName(node.returnContinuation);
-      String body = indentBlock(() => visit(node.body));
+      namer.useReturnName(node.body.returnContinuation);
+      String body = indentBlock(() => visit(node.body.body));
       return '$indentation(FieldDefinition $name (return)\n'
              '$body)';
     } else {