Mark optimized modulo and memcpy code pages -w after writing them.

src/ia32/codegen-ia32.cc

 // 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 237 matching lines @@
     __ pop(esi);
     __ pop(edi);
     __ ret(0);
   }
 
   CodeDesc desc;
   masm.GetCode(&desc);
   ASSERT(desc.reloc_size == 0);
 
   CPU::FlushICache(buffer, actual_size);
+  OS::ProtectCode(buffer, actual_size);
   return FUNCTION_CAST<OS::MemCopyFunction>(buffer);
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32