dart2js cps: Direct access on JS arrays.

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

Index: pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart b/pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart
index 1c5adcfb262a5b7b67d9f2f12ebfd145e0331a93..24fdebc7c04909ac93d3ec9905f428b3a5a8c376 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart
@@ -192,20 +192,18 @@ class IRTracer extends TracerUtil implements cps_ir.Visitor {
   }
 
   visitLiteralList(cps_ir.LiteralList node) {
-    String dummy = names.name(node);
     String values = node.values.map(formatReference).join(', ');
-    printStmt(dummy, "LiteralList ($values)");
+    return "LiteralList ($values)";
   }
 
   visitLiteralMap(cps_ir.LiteralMap node) {
-    String dummy = names.name(node);
     List<String> entries = new List<String>();
     for (cps_ir.LiteralMapEntry entry in node.entries) {
       String key = formatReference(entry.key);
       String value = formatReference(entry.value);
       entries.add("$key: $value");
     }
-    printStmt(dummy, "LiteralMap (${entries.join(', ')})");
+    return "LiteralMap (${entries.join(', ')})";
   }
 
   visitTypeCast(cps_ir.TypeCast node) {
@@ -374,6 +372,24 @@ class IRTracer extends TracerUtil implements cps_ir.Visitor {
     printStmt(id, "ForeignCode ${node.type} ${node.codeTemplate.source} "
         "$arguments $continuation");
   }
+
+  visitGetLength(cps_ir.GetLength node) {
+    String object = formatReference(node.object);
+    return 'GetLength $object';
+  }
+
+  visitGetIndex(cps_ir.GetIndex node) {
+    String object = formatReference(node.object);
+    String index = formatReference(node.index);
+    return 'GetIndex $object $index';
+  }
+
+  visitSetIndex(cps_ir.SetIndex node) {
+    String object = formatReference(node.object);
+    String index = formatReference(node.index);
+    String value = formatReference(node.value);
+    return 'SetIndex $object $index $value';
+  }
 }
 
 /**
@@ -633,6 +649,18 @@ class BlockCollector implements cps_ir.Visitor {
     unexpectedNode(node);
   }
 
+  visitGetLength(cps_ir.GetLength node) {
+    unexpectedNode(node);
+  }
+
+  visitGetIndex(cps_ir.GetIndex node) {
+    unexpectedNode(node);
+  }
+
+  visitSetIndex(cps_ir.SetIndex node) {
+    unexpectedNode(node);
+  }
+
   @override
   visitForeignCode(cps_ir.ForeignCode node) {
     if (node.continuation != null) {