[turbofan] Add support for loading missing properties.

src/compiler/property-access-info.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_PROPERTY_ACCESS_INFO_H_
 #define V8_COMPILER_PROPERTY_ACCESS_INFO_H_
 
 #include <iosfwd>
 
 #include "src/field-index.h"
@@ skipping 14 matching lines @@
 // Whether we are loading a property or storing to a property.
 enum class PropertyAccessMode { kLoad, kStore };
 
 std::ostream& operator<<(std::ostream&, PropertyAccessMode);
 
 
 // This class encapsulates all information required to access a certain
 // object property, either on the object itself or on the prototype chain.
 class PropertyAccessInfo final {
  public:
-  enum Kind { kInvalid, kDataConstant, kDataField };
+  enum Kind { kInvalid, kNotFound, kDataConstant, kDataField };
 
+  static PropertyAccessInfo NotFound(Type* receiver_type,
+                                     MaybeHandle<JSObject> holder);
   static PropertyAccessInfo DataConstant(Type* receiver_type,
                                          Handle<Object> constant,
-                                         MaybeHandle<JSObject> holder) {
-    return PropertyAccessInfo(holder, constant, receiver_type);
-  }
+                                         MaybeHandle<JSObject> holder);
   static PropertyAccessInfo DataField(
       Type* receiver_type, FieldIndex field_index, Type* field_type,
       MaybeHandle<JSObject> holder = MaybeHandle<JSObject>(),
-      MaybeHandle<Map> transition_map = MaybeHandle<Map>()) {
-    return PropertyAccessInfo(holder, transition_map, field_index, field_type,
-                              receiver_type);
-  }
+      MaybeHandle<Map> transition_map = MaybeHandle<Map>());
 
   PropertyAccessInfo();
 
+  bool IsNotFound() const { return kind() == kNotFound; }
   bool IsDataConstant() const { return kind() == kDataConstant; }
   bool IsDataField() const { return kind() == kDataField; }
 
+  bool HasTransitionMap() const { return !transition_map().is_null(); }
+
   Kind kind() const { return kind_; }
   MaybeHandle<JSObject> holder() const { return holder_; }
   MaybeHandle<Map> transition_map() const { return transition_map_; }
   Handle<Object> constant() const { return constant_; }
   FieldIndex field_index() const { return field_index_; }
   Type* field_type() const { return field_type_; }
   Type* receiver_type() const { return receiver_type_; }
 
-  bool HasTransitionMap() const { return !transition_map().is_null(); }
-
  private:
+  PropertyAccessInfo(MaybeHandle<JSObject> holder, Type* receiver_type);
   PropertyAccessInfo(MaybeHandle<JSObject> holder, Handle<Object> constant,
                      Type* receiver_type);
   PropertyAccessInfo(MaybeHandle<JSObject> holder,
                      MaybeHandle<Map> transition_map, FieldIndex field_index,
                      Type* field_type, Type* receiver_type);
 
   Kind kind_;
   Type* receiver_type_;
   Handle<Object> constant_;
   MaybeHandle<Map> transition_map_;
@@ skipping 36 matching lines @@
   Zone* const zone_;
 
   DISALLOW_COPY_AND_ASSIGN(PropertyAccessInfoFactory);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_PROPERTY_ACCESS_INFO_H_