Enable extra API checks, add a check for zapped global handles

src/api.h

 // 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 276 matching lines @@
 
 #undef MAKE_TO_LOCAL
 
 
 // Implementations of OpenHandle
 
 #define MAKE_OPEN_HANDLE(From, To)                                          \
   v8::internal::Handle<v8::internal::To> Utils::OpenHandle(                 \
     const v8::From* that, bool allow_empty_handle) {                        \
     EXTRA_CHECK(allow_empty_handle || that != NULL);                        \
+    EXTRA_CHECK(that == NULL ||                                             \
+        !(*reinterpret_cast<v8::internal::To**>(                            \
+            const_cast<v8::From*>(that)))->IsFailure());                    \
     return v8::internal::Handle<v8::internal::To>(                          \
         reinterpret_cast<v8::internal::To**>(const_cast<v8::From*>(that))); \
   }
 
 OPEN_HANDLE_LIST(MAKE_OPEN_HANDLE)
 
 #undef MAKE_OPEN_HANDLE
 #undef OPEN_HANDLE_LIST
 
 
@@ skipping 282 matching lines @@
     stress_type_ = stress_type;
   }
 
  private:
   static v8::Testing::StressType stress_type_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_API_H_