Reapply keyed load cache probing in generated code. I introduced a...

src/heap.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 1282 matching lines @@
 class KeyedLookupCache {
  public:
   // Lookup field offset for (map, name). If absent, -1 is returned.
   static int Lookup(Map* map, String* name);
 
   // Update an element in the cache.
   static void Update(Map* map, String* name, int field_offset);
 
   // Clear the cache.
   static void Clear();
+
+  static const int kLength = 64;
+  static const int kCapacityMask = kLength - 1;
+  static const int kMapHashShift = 2;
+
  private:
   static inline int Hash(Map* map, String* name);
-  static const int kLength = 64;
+
+  // Get the address of the keys and field_offsets arrays.  Used in
+  // generated code to perform cache lookups.
+  static Address keys_address() {
+    return reinterpret_cast<Address>(&keys_);
+  }
+
+  static Address field_offsets_address() {
+    return reinterpret_cast<Address>(&field_offsets_);
+  }
+
   struct Key {
     Map* map;
     String* name;
   };
   static Key keys_[kLength];
   static int field_offsets_[kLength];
+
+  friend class ExternalReference;
 };
 
 
-
 // Cache for mapping (array, property name) into descriptor index.
 // The cache contains both positive and negative results.
 // Descriptor index equals kNotFound means the property is absent.
 // Cleared at startup and prior to any gc.
 class DescriptorLookupCache {
  public:
   // Lookup descriptor index for (map, name).
   // If absent, kAbsent is returned.
   static int Lookup(DescriptorArray* array, String* name) {
     if (!StringShape(name).IsSymbol()) return kAbsent;
@@ skipping 333 matching lines @@
 
   // To speed up scavenge collections new space string are kept
   // separate from old space strings.
   static List<Object*> new_space_strings_;
   static List<Object*> old_space_strings_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_