Add hash fields to code cache header.

src/flags.cc

 // Copyright 2006-2008 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 <cctype>
 #include <cstdlib>
 #include <sstream>
 
 #include "src/v8.h"
 
@@ skipping 538 matching lines @@
 #include "src/flag-definitions.h"
 #undef FLAG_MODE_DEFINE_IMPLICATIONS
 }
 
 
 uint32_t FlagList::Hash() {
   std::ostringstream modified_args_as_string;
   for (size_t i = 0; i < num_flags; ++i) {
     Flag* current = &flags[i];
     if (!current->IsDefault()) {
+      modified_args_as_string << i;
       modified_args_as_string << *current;
     }
   }
   std::string args(modified_args_as_string.str());
   return static_cast<uint32_t>(
       base::hash_range(args.c_str(), args.c_str() + args.length()));
 }
 } }  // namespace v8::internal