Right now it's not clear that the dummy field that is injected into empty inline klasses can be/is reused for the null-marker when looking at the printed layout from -XX:+PrintInlineLayout. I suggest we enhance this print to indicate if the dummy field has been reused for the null-marker.

Before:
Instance fields:
 @0 RESERVED 12/-
 @12 REGULAR 1/1 ".empty" B

After:
Instance fields:
 @0 RESERVED 12/-
 @12 REGULAR 1/1 ".empty" B (reused as null-marker)