Don't duplicate OS::ActivationFrameAlignment() for every POSIX platform.

src/platform-linux.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 290 matching lines @@
     }
   }
   fclose(f);
 
   // Did not find string in the proc file.
   return false;
 }
 #endif  // def __mips__
 
 
-int OS::ActivationFrameAlignment() {
-#if V8_TARGET_ARCH_ARM
-  // On EABI ARM targets this is required for fp correctness in the
-  // runtime system.
-  return 8;
-#elif V8_TARGET_ARCH_MIPS
-  return 8;
-#endif
-  // 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));
   struct tm* t = localtime(&tv);
   if (NULL == t) return "";
   return t->tm_zone;
 }
 
 
 double OS::LocalTimeOffset() {
@@ skipping 439 matching lines @@
   limit_mutex = CreateMutex();
 }
 
 
 void OS::TearDown() {
   delete limit_mutex;
 }
 
 
 } }  // namespace v8::internal