Fix details in message formatting.

src/messages.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 172 matching lines @@
   return result;
 }
 
 
 function NoSideEffectToString(obj) {
   if (IS_STRING(obj)) return obj;
   if (IS_NUMBER(obj)) return %_NumberToString(obj);
   if (IS_BOOLEAN(obj)) return x ? 'true' : 'false';
   if (IS_UNDEFINED(obj)) return 'undefined';
   if (IS_NULL(obj)) return 'null';
+  if (IS_FUNCTION(obj)) return  %_CallFunction(obj, FunctionToString);
   if (IS_OBJECT(obj) && %GetDataProperty(obj, "toString") === ObjectToString) {
     var constructor = obj.constructor;
     if (typeof constructor == "function") {
       var constructorName = constructor.name;
       if (IS_STRING(constructorName) && constructorName !== "") {
         return "#<" + constructorName + ">";
       }
     }
   }
   if (IsNativeErrorObject(obj)) return %_CallFunction(obj, ErrorToString);
@@ skipping 1062 matching lines @@
     %DefineOrRedefineDataProperty(this, 'stack', v, NONE);
   }
 
   %DefineOrRedefineAccessorProperty(
       boilerplate, 'stack', getter, setter, DONT_ENUM);
 
   return boilerplate;
 }
 
 var kStackOverflowBoilerplate = SetUpStackOverflowBoilerplate();