Fix for Clusterfuzz issue 343928.

src/objects.cc

 // Copyright 2013 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 5425 matching lines @@
             return true;
           }
         } else if (ctxobj == obj) {
           return true;
         }
       }
     }
 
     // Check the context extension (if any) if it can have references.
     if (context->has_extension() && !context->IsCatchContext()) {
+      // With harmony scoping, a JSFunction may have a global context.
+      // TODO(mvstanton): walk into the ScopeInfo.
+      if (FLAG_harmony_scoping && context->IsGlobalContext()) {
+        return false;
+      }
+
       return JSObject::cast(context->extension())->ReferencesObject(obj);
     }
   }
 
   // No references to object.
   return false;
 }
 
 
 Handle<Object> JSObject::PreventExtensions(Handle<JSObject> object) {
@@ skipping 11025 matching lines @@
 #define ERROR_MESSAGES_TEXTS(C, T) T,
   static const char* error_messages_[] = {
       ERROR_MESSAGES_LIST(ERROR_MESSAGES_TEXTS)
   };
 #undef ERROR_MESSAGES_TEXTS
   return error_messages_[reason];
 }
 
 
 } }  // namespace v8::internal