--- old/src/hotspot/share/oops/arrayKlass.cpp	2018-05-21 11:52:06.495963456 +0200
+++ new/src/hotspot/share/oops/arrayKlass.cpp	2018-05-21 11:52:06.195958111 +0200
@@ -94,6 +94,7 @@
     set_layout_helper(Klass::_lh_neutral_value);
     set_is_cloneable(); // All arrays are considered to be cloneable (See JLS 20.1.5)
     TRACE_INIT_ID(this);
+    assert(!ptr_is_value_type(this), "ArrayKlass encoded as value type");
 }
 
 Symbol* ArrayKlass::create_element_klass_array_name(Klass* element_klass, TRAPS) {