Move platform abstraction to base library

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 171 matching lines @@
   static inline bool SupportsCrankshaft();
 
   static inline unsigned cache_line_size() {
     ASSERT(cache_line_size_ != 0);
     return cache_line_size_;
   }
 
   static void PrintTarget();
   static void PrintFeatures();
 
+  // Flush instruction cache.
+  static void FlushICache(void* start, size_t size);
+
  private:
   // Platform-dependent implementation.
   static void ProbeImpl(bool cross_compile);
 
   static unsigned supported_;
   static unsigned cache_line_size_;
   static bool initialized_;
   friend class ExternalReference;
   DISALLOW_COPY_AND_ASSIGN(CpuFeatures);
 };
@@ skipping 948 matching lines @@
 
  private:
   int32_t multiplier_;
   int32_t shift_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ASSEMBLER_H_