Don't duplicate OS::CpuFeaturesImpliedByPlatform for every POSIX platform.

src/platform-openbsd.cc

 // Copyright 2012 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 73 matching lines @@
     // variety of ASLR modes (PAE kernel, NX compat mode, etc).
     raw_addr &= 0x3ffff000;
     raw_addr += 0x20000000;
 #endif
     return reinterpret_cast<void*>(raw_addr);
   }
   return NULL;
 }
 
 
-uint64_t OS::CpuFeaturesImpliedByPlatform() {
-  return 0;
-}
-
-
 int OS::ActivationFrameAlignment() {
   // With gcc 4.4 the tree vectorization optimizer can generate code
   // that requires 16 byte alignment such as movdqa on x86.
   return 16;
 }
 
 
 const char* OS::LocalTimezone(double time) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(floor(time/msPerSecond));
@@ skipping 435 matching lines @@
   limit_mutex = CreateMutex();
 }
 
 
 void OS::TearDown() {
   delete limit_mutex;
 }
 
 
 } }  // namespace v8::internal