In InlineKlass, the method null_marker_offset() method returns the offset of the null marker of a value class.
But in InstanceKlass, the method null_marker_offset(int i) returns the offset of the null marker for the field at index i in the current class. This method is not explicit enough that it applies to a field the class and not the class itself. To be consistent with other methods related to the fields of the class, the method should be named field_null_marker_offset(int i).