--- old/src/share/vm/opto/type.cpp	2017-06-20 21:25:51.197630551 +0200
+++ new/src/share/vm/opto/type.cpp	2017-06-20 21:25:47.287641956 +0200
@@ -2023,7 +2023,7 @@
   if (vt_fields_as_args) {
     for (int i = 0; i < sig->count(); i++) {
       ciType* type = sig->type_at(i);
-      if (type->basic_type() == T_VALUETYPE) {
+      if (type->basic_type() == T_VALUETYPE && type != ciEnv::current()->___Value_klass()) {
         assert(type->is_valuetype(), "inconsistent type");
         ciValueKlass* vk = (ciValueKlass*)type;
         vt_extra += vk->value_arg_slots()-1;
@@ -2081,8 +2081,7 @@
       break;
     case T_VALUETYPE: {
       assert(type->is_valuetype(), "inconsistent type");
-      assert(type != ciEnv::current()->___Value_klass(), "unsupported");
-      if (vt_fields_as_args) {
+      if (vt_fields_as_args && type != ciEnv::current()->___Value_klass()) {
         ciValueKlass* vk = (ciValueKlass*)type;
         collect_value_fields(vk, field_array, pos);
       } else {