Improve memory usage of receiver type feedback.

src/hydrogen-instructions.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 3387 matching lines @@
  private:
   bool is_in_object_;
   int offset_;
 };
 
 
 class HLoadNamedFieldPolymorphic: public HTemplateInstruction<2> {
  public:
   HLoadNamedFieldPolymorphic(HValue* context,
                              HValue* object,
-                             ZoneMapList* types,
+                             SmallMapList* types,
                              Handle<String> name);
 
   HValue* context() { return OperandAt(0); }
   HValue* object() { return OperandAt(1); }
-  ZoneMapList* types() { return &types_; }
+  SmallMapList* types() { return &types_; }
   Handle<String> name() { return name_; }
   bool need_generic() { return need_generic_; }
 
   virtual Representation RequiredInputRepresentation(int index) const {
     return Representation::Tagged();
   }
 
   virtual void PrintDataTo(StringStream* stream);
 
   DECLARE_CONCRETE_INSTRUCTION(LoadNamedFieldPolymorphic)
 
   static const int kMaxLoadPolymorphism = 4;
 
  protected:
   virtual bool DataEquals(HValue* value);
 
  private:
-  ZoneMapList types_;
+  SmallMapList types_;
   Handle<String> name_;
   bool need_generic_;
 };
 
 
 
 class HLoadNamedGeneric: public HTemplateInstruction<2> {
  public:
   HLoadNamedGeneric(HValue* context, HValue* object, Handle<Object> name)
       : name_(name) {
@@ skipping 745 matching lines @@
 
   DECLARE_CONCRETE_INSTRUCTION(In)
 };
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_