Allow platforms (linux and win32) to not force 16-byte alignment...

src/platform.h

 // Copyright 2006-2008 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 199 matching lines @@
   static char* StrDup(const char* str);
 
   // Support for profiler.  Can do nothing, in which case ticks
   // occuring in shared libraries will not be properly accounted
   // for.
   static void LogSharedLibraryAddresses();
 
   // Returns the double constant NAN
   static double nan_value();
 
+  // Returns the activation frame alignment constraint or zero if
+  // the platform doesn't care. Guaranteed to be a power of two.
+  static int ActivationFrameAlignment();
+
  private:
   static const int msPerSecond = 1000;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(OS);
 };
 
 
 class VirtualMemory {
  public:
   // Reserves virtual memory with size.
@@ skipping 207 matching lines @@
   bool active_;
   PlatformData* data_;  // Platform specific data.
   DISALLOW_IMPLICIT_CONSTRUCTORS(Sampler);
 };
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal
 
 #endif  // V8_PLATFORM_H_