Migrate instance of deprecated maps in HCheckMaps.

src/objects-inl.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 3599 matching lines @@
   set_bit_field3(Deprecated::update(bit_field3(), true));
 }
 
 
 bool Map::is_deprecated() {
   if (!FLAG_track_fields) return false;
   return Deprecated::decode(bit_field3());
 }
 
 
+void Map::set_migration_target(bool value) {
+  set_bit_field3(IsMigrationTarget::update(bit_field3(), value));
+}
+
+
+bool Map::is_migration_target() {
+  if (!FLAG_track_fields) return false;
+  return IsMigrationTarget::decode(bit_field3());
+}
+
+
 void Map::freeze() {
   set_bit_field3(IsFrozen::update(bit_field3(), true));
 }
 
 
 bool Map::is_frozen() {
   return IsFrozen::decode(bit_field3());
 }
 
 
@@ skipping 578 matching lines @@
 
 
 void Map::InitializeDescriptors(DescriptorArray* descriptors) {
   int len = descriptors->number_of_descriptors();
   set_instance_descriptors(descriptors);
   SetNumberOfOwnDescriptors(len);
 }
 
 
 ACCESSORS(Map, instance_descriptors, DescriptorArray, kDescriptorsOffset)
-SMI_ACCESSORS(Map, bit_field3, kBitField3Offset)
+
+
+void Map::set_bit_field3(uint32_t bits) {
+  // Ensure the upper 2 bits have the same value by sign extending it. This is
+  // necessary to be able to use the 31st bit.
+  int value = bits << 1;
+  WRITE_FIELD(this, kBitField3Offset, Smi::FromInt(value >> 1));
+}
+
+
+uint32_t Map::bit_field3() {
+  Object* value = READ_FIELD(this, kBitField3Offset);
+  return Smi::cast(value)->value();
+}
 
 
 void Map::ClearTransitions(Heap* heap, WriteBarrierMode mode) {
   Object* back_pointer = GetBackPointer();
 
   if (Heap::ShouldZapGarbage() && HasTransitionArray()) {
     ZapTransitions();
   }
 
   WRITE_FIELD(this, kTransitionsOrBackPointerOffset, back_pointer);
@@ skipping 2008 matching lines @@
 #undef WRITE_UINT32_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_