Make Failure inherit from MaybeObject instead of Object.

src/execution.h

 // Copyright 2006-2008 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 114 matching lines @@
                                           Handle<JSFunction> fun,
                                           Handle<Object> pos,
                                           Handle<Object> is_global);
 #ifdef ENABLE_DEBUGGER_SUPPORT
   static Object* DebugBreakHelper();
   static void ProcessDebugMesssages(bool debug_command_only);
 #endif
 
   // If the stack guard is triggered, but it is not an actual
   // stack overflow, then handle the interruption accordingly.
-  static Object* HandleStackGuardInterrupt();
+  MUST_USE_RESULT static MaybeObject* HandleStackGuardInterrupt();
 
   // Get a function delegate (or undefined) for the given non-function
   // object. Used for support calling objects as functions.
   static Handle<Object> GetFunctionDelegate(Handle<Object> object);
 
   // Get a function delegate (or undefined) for the given non-function
   // object. Used for support calling objects as constructors.
   static Handle<Object> GetConstructorDelegate(Handle<Object> object);
 };
 
@@ skipping 186 matching lines @@
       v8::Handle<v8::String> name);
   static v8::Handle<v8::Value> Externalize(const v8::Arguments& args);
   static v8::Handle<v8::Value> IsAscii(const v8::Arguments& args);
  private:
   static const char* const kSource;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_EXECUTION_H_