[runtime][ic] Constant field tracking support.

src/ic/handler-configuration.h

 // Copyright 2016 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_IC_HANDLER_CONFIGURATION_H_
 #define V8_IC_HANDLER_CONFIGURATION_H_
 
 #include "src/elements-kind.h"
 #include "src/field-index.h"
 #include "src/globals.h"
@@ skipping 103 matching lines @@
                                            bool convert_hole_to_undefined,
                                            bool is_js_array);
 };
 
 // A set of bit fields representing Smi handlers for stores.
 class StoreHandler {
  public:
   enum Kind {
     kStoreElement,
     kStoreField,
+    kStoreConstField,
     kTransitionToField,
-    kTransitionToConstant
+    // TODO(ishell): remove once constant field tracking is done.
+    kTransitionToConstant = kStoreConstField
   };
   class KindBits : public BitField<Kind, 0, 2> {};
 
   enum FieldRepresentation { kSmi, kDouble, kHeapObject, kTagged };
 
   // Applicable to kStoreField, kTransitionToField and kTransitionToConstant
   // kinds.
 
   // Index of a value entry in the descriptor array.
   // +2 here is because each descriptor entry occupies 3 slots in array.
@@ skipping 32 matching lines @@
   // The layout of an array handler representing a transitioning store
   // when prototype chain checks include non-existing lookups and access checks.
   static const int kSmiHandlerIndex = 0;
   static const int kValidityCellIndex = 1;
   static const int kTransitionCellIndex = 2;
   static const int kFirstPrototypeIndex = 3;
 
   // Creates a Smi-handler for storing a field to fast object.
   static inline Handle<Object> StoreField(Isolate* isolate, int descriptor,
                                           FieldIndex field_index,
+                                          PropertyConstness constness,
                                           Representation representation);
 
   // Creates a Smi-handler for transitioning store to a field.
   static inline Handle<Object> TransitionToField(Isolate* isolate,
                                                  int descriptor,
                                                  FieldIndex field_index,
                                                  Representation representation,
                                                  bool extend_storage);
 
   // Creates a Smi-handler for transitioning store to a constant field (in this
   // case the only thing that needs to be done is an update of a map).
   static inline Handle<Object> TransitionToConstant(Isolate* isolate,
                                                     int descriptor);
 
  private:
   static inline Handle<Object> StoreField(Isolate* isolate, Kind kind,
                                           int descriptor,
                                           FieldIndex field_index,
                                           Representation representation,
                                           bool extend_storage);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_IC_HANDLER_CONFIGURATION_H_