Companion

Create a new AvailObject with the specified descriptor]AbstractDescriptor, the specified number of object slots, and the specified number of long slots. Also copy the fields from the specified object, which must have a descriptor of the same class. If the sizes of the long arrays differ, only transfer the minimum of the two sizes; do the same for the object slots.

This static switch enables paranoid checks to ensure objects are only being accessed via slot definitions appropriate for the object's actual descriptor. This check slows the system considerably, but it's occasionally valuable to enable for a short time, especially right after introducing new descriptor subclasses.