Suggested change in jni_SetObjectArrayElement

2398 - Klass* ek = a->is_flatArray() ? FlatArrayKlass::cast(a->klass())->element_klass() : RefArrayKlass::cast(a->klass())->element_klass();
2398 + assert(a->klass()->is_refined_objArray_klass(), "must be");
2399 + Klass* ek = ObjArrayKlass::cast(a->klass())->element_klass();

https://github.com/openjdk/valhalla/pull/2190/files#r2876426566