Make Failure inherit from MaybeObject instead of Object.

test/cctest/test-strings.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 
 // Check that we can traverse very deep stacks of ConsStrings using
 // StringInputBuffer.  Check that Get(int) works on very deep stacks
 // of ConsStrings.  These operations may not be very fast, but they
 // should be possible without getting errors due to too deep recursion.
 
 #include <stdlib.h>
 
 #include "v8.h"
@@ skipping 458 matching lines @@
   };
 
   const char* line;
   for (int i = 0; (line = lines[i]); i++) {
     printf("%s\n", line);
     v8::Local<v8::Value> result =
         v8::Script::Compile(v8::String::New(line))->Run();
     CHECK_EQ(results[i]->IsUndefined(), result->IsUndefined());
     CHECK_EQ(results[i]->IsNumber(), result->IsNumber());
     if (result->IsNumber()) {
-      CHECK_EQ(Smi::cast(results[i]->ToSmi())->value(),
+      CHECK_EQ(Smi::cast(results[i]->ToSmi()->ToObjectChecked())->value(),
                result->ToInt32()->Value());
     }
   }
 }