Remove parent_level field of function type parameters.

runtime/vm/clustered_snapshot.cc

Index: runtime/vm/clustered_snapshot.cc
diff --git a/runtime/vm/clustered_snapshot.cc b/runtime/vm/clustered_snapshot.cc
index d57951938a1e4f10af0e618cdd004df720061119..b4738f4a1c52f429405a154c508772397be5d123 100644
--- a/runtime/vm/clustered_snapshot.cc
+++ b/runtime/vm/clustered_snapshot.cc
@@ -3189,7 +3189,6 @@ class TypeParameterSerializationCluster : public SerializationCluster {
       s->Write<int32_t>(type->ptr()->parameterized_class_id_);
       s->WriteTokenPosition(type->ptr()->token_pos_);
       s->Write<int16_t>(type->ptr()->index_);
-      s->Write<uint8_t>(type->ptr()->parent_level_);
       s->Write<int8_t>(type->ptr()->type_state_);
     }
   }
@@ -3231,7 +3230,6 @@ class TypeParameterDeserializationCluster : public DeserializationCluster {
       type->ptr()->parameterized_class_id_ = d->Read<int32_t>();
       type->ptr()->token_pos_ = d->ReadTokenPosition();
       type->ptr()->index_ = d->Read<int16_t>();
-      type->ptr()->parent_level_ = d->Read<uint8_t>();
       type->ptr()->type_state_ = d->Read<int8_t>();
     }
   }
@@ -4755,6 +4753,7 @@ void Serializer::AddVMIsolateBaseObjects() {
   AddBaseObject(Object::null());
   AddBaseObject(Object::sentinel().raw());
   AddBaseObject(Object::transition_sentinel().raw());
+  AddBaseObject(Object::empty_type_arguments().raw());
   AddBaseObject(Object::empty_array().raw());
   AddBaseObject(Object::zero_array().raw());
   AddBaseObject(Object::dynamic_type().raw());
@@ -5159,6 +5158,7 @@ void Deserializer::AddVMIsolateBaseObjects() {
   AddBaseObject(Object::null());
   AddBaseObject(Object::sentinel().raw());
   AddBaseObject(Object::transition_sentinel().raw());
+  AddBaseObject(Object::empty_type_arguments().raw());
   AddBaseObject(Object::empty_array().raw());
   AddBaseObject(Object::zero_array().raw());
   AddBaseObject(Object::dynamic_type().raw());