dart2js cps: Scalar replacement of aggregates

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

Index: pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
index 24938d43fc8d9cdd8342d984e711759189f30a43..3088260b14bf50261baa59987779b7b58c93468b 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart
@@ -716,6 +716,8 @@ class GetField extends Primitive {
 
   bool get isSafeForElimination => objectIsNotNull;
   bool get isSafeForReordering => false;
+
+  toString() => 'GetField($field)';
 }
 
 /// Get the length of a string or native list.
@@ -865,6 +867,8 @@ class CreateInstance extends Primitive {
 
   bool get isSafeForElimination => true;
   bool get isSafeForReordering => true;
+
+  toString() => 'CreateInstance($classElement)';
 }
 
 class Interceptor extends Primitive {