Make accessors for oddball objects return Oddball* instead of Object*.

src/v8utils.h

 // Copyright 2011 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 124 matching lines @@
   } else {
     int remaining = num_words;
     do {
       remaining--;
       *dst++ = *src++;
     } while (remaining > 0);
   }
 }
 
 
-template <typename T>
-static inline void MemsetPointer(T** dest, T* value, int counter) {
+template <typename T, typename U>
+static inline void MemsetPointer(T** dest, U* value, int counter) {
+#ifdef DEBUG
+  T* a = NULL;
+  U* b = NULL;
+  a = b;  // Fake assignment to check assignability.
+  USE(a);
+#endif  // DEBUG
 #if defined(V8_HOST_ARCH_IA32)
 #define STOS "stosl"
 #elif defined(V8_HOST_ARCH_X64)
 #define STOS "stosq"
 #endif
 
 #if defined(__GNUC__) && defined(STOS)
   asm volatile(
       "cld;"
       "rep ; " STOS
@@ skipping 104 matching lines @@
 
   // Add formatted contents like printf based on a va_list.
   void AddFormattedList(const char* format, va_list list);
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(StringBuilder);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_V8UTILS_H_