Implement basic array prefetching hints in Hydrogen.

src/hydrogen.h

 // 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 1307 matching lines @@
         present_flags_(0),
         array_(NULL),
         lists_(NULL),
         free_list_head_(kNil) {
     ResizeLists(kInitialSize, zone);
     Resize(kInitialSize, zone);
   }
 
   void Kill(GVNFlagSet flags);
 
+  void KillAll();
+
   void Add(HValue* value, Zone* zone) {
     present_flags_.Add(value->gvn_flags());
     Insert(value, zone);
   }
 
   HValue* Lookup(HValue* value) const;
 
   HValueMap* Copy(Zone* zone) const {
     return new(zone) HValueMap(zone, this);
   }
@@ skipping 217 matching lines @@
   const char* filename_;
   HeapStringAllocator string_allocator_;
   StringStream trace_;
   int indent_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_H_