Implement HChange support for Smis and use it in Load/StoreNameField

src/property-details.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 113 matching lines @@
   Representation generalize(Representation other) {
     if (other.fits_into(*this)) return *this;
     if (other.is_more_general_than(*this)) return other;
     return Representation::Tagged();
   }
 
   Kind kind() const { return static_cast<Kind>(kind_); }
   bool IsNone() const { return kind_ == kNone; }
   bool IsTagged() const { return kind_ == kTagged; }
   bool IsSmi() const { return kind_ == kSmi; }
+  bool IsSmiOrTagged() const { return IsSmi() || IsTagged(); }
   bool IsInteger32() const { return kind_ == kInteger32; }
   bool IsDouble() const { return kind_ == kDouble; }
   bool IsHeapObject() const { return kind_ == kHeapObject; }
   bool IsExternal() const { return kind_ == kExternal; }
   bool IsSpecialization() const {
     return kind_ == kInteger32 || kind_ == kDouble;
   }
   const char* Mnemonic() const;
 
  private:
@@ skipping 93 matching lines @@
     value_ = RepresentationField::update(
         value, EncodeRepresentation(representation));
   }
 
   uint32_t value_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_PROPERTY_DETAILS_H_