Fix windows build.

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 32 matching lines @@
 #include "isolate.h"
 #include "runtime.h"
 #include "token.h"
 
 namespace v8 {
 
 class ApiFunction;
 
 namespace internal {
 
-struct StatsCounter;
+class StatsCounter;
 // -----------------------------------------------------------------------------
 // Platform independent assembler base class.
 
 class AssemblerBase: public Malloced {
  public:
   AssemblerBase(Isolate* isolate, void* buffer, int buffer_size);
   virtual ~AssemblerBase();
 
   Isolate* isolate() const { return isolate_; }
   int jit_cookie() const { return jit_cookie_; }
@@ skipping 967 matching lines @@
  public:
   NullCallWrapper() { }
   virtual ~NullCallWrapper() { }
   virtual void BeforeCall(int call_size) const { }
   virtual void AfterCall() const { }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ASSEMBLER_H_