ES6 symbols: turn symbols into a proper primitive type

src/v8natives.js

Index: src/v8natives.js
diff --git a/src/v8natives.js b/src/v8natives.js
index 24ad22d96d1d530121452d1d83cb7bf21dff8344..a382350f242c3c4375bbf82f3f8ee4d47115219c 100644
--- a/src/v8natives.js
+++ b/src/v8natives.js
@@ -233,7 +233,6 @@ $Object.prototype.constructor = $Object;
 function ObjectToString() {
   if (IS_UNDEFINED(this) && !IS_UNDETECTABLE(this)) return "[object Undefined]";
   if (IS_NULL(this)) return "[object Null]";
-  if (IS_SYMBOL(this)) return "[object Symbol]";
   return "[object " + %_ClassOf(ToObject(this)) + "]";
 }
 
@@ -865,7 +864,7 @@ function DefineArrayProperty(obj, p, desc, should_throw) {
   // DefineObjectProperty() to modify its value.
 
   // Step 3 - Special handling for length property.
-  if (p == "length") {
+  if (!IS_SYMBOL(p) && p == "length") {
     var length = obj.length;
     if (!desc.hasValue()) {
       return DefineObjectProperty(obj, "length", desc, should_throw);