Move aligned allocation to the platform files.

src/platform.h

 // 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 345 matching lines @@
   size_t size() { return size_; }
 
   // Commits real memory. Returns whether the operation succeeded.
   bool Commit(void* address, size_t size, bool is_executable);
 
   // Uncommit real memory.  Returns whether the operation succeeded.
   bool Uncommit(void* address, size_t size);
 
   static void* ReserveRegion(size_t size);
 
+  static void* ReserveAlignedRegion(size_t size, size_t alignment);
+
   static bool CommitRegion(void* base, size_t size, bool is_executable);
 
   static bool UncommitRegion(void* base, size_t size);
 
   static bool ReleaseRegion(void* base, size_t size);
 
  private:
   void* address_;  // Start address of the virtual memory.
   size_t size_;  // Size of the virtual memory.
 };
@@ skipping 293 matching lines @@
   Atomic32 active_;
   PlatformData* data_;  // Platform specific data.
   int samples_taken_;  // Counts stack samples taken.
   DISALLOW_IMPLICIT_CONSTRUCTORS(Sampler);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_PLATFORM_H_