Tag all prototypes as proto, except those set using __proto__

src/v8natives.js

Index: src/v8natives.js
diff --git a/src/v8natives.js b/src/v8natives.js
index 8484150248a13a2ef01467da31603fab1db88b0c..a8f107f6d2a54317c3a5b00d505c320cb196f6b4 100644
--- a/src/v8natives.js
+++ b/src/v8natives.js
@@ -96,7 +96,7 @@ function SetUpLockedPrototype(constructor, fields, methods) {
     %AddNamedProperty(prototype, key, f, DONT_ENUM | DONT_DELETE | READ_ONLY);
     %SetNativeFlag(f);
   }
-  %SetPrototype(prototype, null);
+  %InternalSetPrototype(prototype, null);
   %ToFastProperties(prototype);
 }
 
@@ -1125,7 +1125,8 @@ function ObjectCreate(proto, properties) {
   if (!IS_SPEC_OBJECT(proto) && proto !== null) {
     throw MakeTypeError("proto_object_or_null", [proto]);
   }
-  var obj = { __proto__: proto };
+  var obj = {};
+  %InternalSetPrototype(obj, proto);
   if (!IS_UNDEFINED(properties)) ObjectDefineProperties(obj, properties);
   return obj;
 }