Tag all prototypes as proto, except those set using __proto__

src/apinatives.js

Index: src/apinatives.js
diff --git a/src/apinatives.js b/src/apinatives.js
index 65dc3cb9608cc574abca2412133f675ba6cc80d5..dda1d24bab2b2014ffd6aabf1eb20914f3924424 100644
--- a/src/apinatives.js
+++ b/src/apinatives.js
@@ -68,7 +68,7 @@ function InstantiateFunction(data, name) {
         // internal ToBoolean doesn't handle that!
         if (typeof parent !== 'undefined') {
           var parent_fun = Instantiate(parent);
-          %SetPrototype(prototype, parent_fun.prototype);
+          %InternalSetPrototype(prototype, parent_fun.prototype);
         }
       }
       var fun = %CreateApiFunction(data, prototype);