Use 0 instead of undefined for uninitialized stub key.

src/objects-debug.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/disasm.h"
 #include "src/disassembler.h"
 #include "src/jsregexp.h"
 #include "src/macro-assembler.h"
@@ skipping 621 matching lines @@
   Address last_gc_pc = NULL;
   Isolate* isolate = GetIsolate();
   for (RelocIterator it(this); !it.done(); it.next()) {
     it.rinfo()->Verify(isolate);
     // Ensure that GC will not iterate twice over the same pointer.
     if (RelocInfo::IsGCRelocMode(it.rinfo()->rmode())) {
       CHECK(it.rinfo()->pc() != last_gc_pc);
       last_gc_pc = it.rinfo()->pc();
     }
   }
-  CHECK(raw_type_feedback_info()->IsUndefined() ||
+  CHECK(raw_type_feedback_info() == Smi::FromInt(0) ||
         raw_type_feedback_info()->IsSmi() == IsCodeStubOrIC());
 }
 
 
 void Code::VerifyEmbeddedObjectsDependency() {
   if (!CanContainWeakObjects()) return;
   DisallowHeapAllocation no_gc;
   Isolate* isolate = GetIsolate();
   HandleScope scope(isolate);
   int mode_mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
@@ skipping 539 matching lines @@
   for (int i = 0; i < number_of_transitions(); ++i) {
     if (!CheckOneBackPointer(current_map, GetTarget(i))) return false;
   }
   return true;
 }
 
 
 #endif  // DEBUG
 
 } }  // namespace v8::internal