The prefix of attribute Finalization_Size must be an object or
a type. This attribute returns the size of any hidden data
reserved by the compiler to handle finalization-related actions. The type of
the attribute is ‘universal_integer’.
Finalization_Size yields a value of zero for a type with no controlled
parts, an object whose type has no controlled parts, or an object of a
class-wide type whose tag denotes a type with no controlled parts.
For a class-wide type, Finalization_Size yields a non-zero value except
if a No_Finalization restriction is in effect, in which case it yields zero.
Note that only heap-allocated objects contain finalization data.