[Isolates] Convert more static data either to read-only or to per-isolate.

src/platform-posix.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 104 matching lines @@
 
 // ----------------------------------------------------------------------------
 // POSIX stdio support.
 //
 
 FILE* OS::FOpen(const char* path, const char* mode) {
   return fopen(path, mode);
 }
 
 
-const char* OS::LogFileOpenMode = "w";
+const char* const OS::LogFileOpenMode = "w";
 
 
 void OS::Print(const char* format, ...) {
   va_list args;
   va_start(args, format);
   VPrint(format, args);
   va_end(args);
 }
 
 
@@ skipping 222 matching lines @@
   return ntohl(value);
 }
 
 
 Socket* OS::CreateSocket() {
   return new POSIXSocket();
 }
 
 
 } }  // namespace v8::internal