Remove the global Strength enum class completely.

src/objects-inl.h

 // Copyright 2012 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.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 4520 matching lines @@
 void Map::set_migration_target(bool value) {
   set_bit_field3(IsMigrationTarget::update(bit_field3(), value));
 }
 
 
 bool Map::is_migration_target() {
   return IsMigrationTarget::decode(bit_field3());
 }
 
 
-void Map::set_is_strong() {
-  set_bit_field3(IsStrong::update(bit_field3(), true));
-}
-
-
-bool Map::is_strong() {
-  return IsStrong::decode(bit_field3());
-}
-
-
 void Map::set_new_target_is_base(bool value) {
   set_bit_field3(NewTargetIsBase::update(bit_field3(), value));
 }
 
 
 bool Map::new_target_is_base() { return NewTargetIsBase::decode(bit_field3()); }
 
 
 void Map::set_construction_counter(int value) {
   set_bit_field3(ConstructionCounter::update(bit_field3(), value));
@@ skipping 3221 matching lines @@
 #undef WRITE_INT64_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_OBJECTS_INL_H_