Try to fix win64 build.

src/log-utils.cc

 // Copyright 2009 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 136 matching lines @@
 static const char kCodeLogExt[] = ".code";
 
 
 void Log::OpenFile(const char* name) {
   ASSERT(!IsEnabled());
   output_handle_ = OS::FOpen(name, OS::LogFileOpenMode);
   if (FLAG_ll_prof) {
     // Open a file for logging the contents of code objects so that
     // they can be disassembled later.
     size_t name_len = strlen(name);
-    ScopedVector<char> code_name(name_len + sizeof(kCodeLogExt));
+    ScopedVector<char> code_name(
+        static_cast<int>(name_len + sizeof(kCodeLogExt)));
     memcpy(code_name.start(), name, name_len);
     memcpy(code_name.start() + name_len, kCodeLogExt, sizeof(kCodeLogExt));
     output_code_handle_ = OS::FOpen(code_name.start(), OS::LogFileOpenMode);
   }
   Write = WriteToFile;
   Init();
 }
 
 
 void Log::OpenMemoryBuffer() {
@@ skipping 335 matching lines @@
     PrintBackwardReference(backref, best.distance, best.copy_from_pos);
     ASSERT(strlen(backref.start()) - best.backref_size == 0);
     prev_record->Truncate(static_cast<int>(unchanged_len + best.backref_size));
   }
   return true;
 }
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal