Summary
-------

This change adds the class file attribute PermittedSubclasses to the list of attributes that cannot be changed by class retransformation or class redefinition.

Problem
-------

Users need to be aware that class retransformation and class redefinition cannot change the PermittedSubclasses attribute.

Solution
--------

The specifications for class redefinition and retransformation, in the JVM TI specification are enhanced to disallow any modification of the PermittedSubclasses attribute.

Specification
-------------

The JVM TI Specification changes are as follows:

      @@ -7680,7 +7680,8 @@
              The retransformation must not add, remove or rename fields or methods, change the
              signatures of methods, change modifiers, or change inheritance.
              The retransformation must not change the <code>NestHost</code>,
     -        <code>NestMembers</code>, or <code>Record</code> attributes.
     +        <code>NestMembers</code>, <code>Record</code>, or <code>PermittedSubclasses</code>
     +        attributes.
              These restrictions may be lifted in future versions.
              See the error return description below for information on error codes
              returned if an unsupported retransformation is attempted.
     @@ -7833,7 +7834,8 @@
              The redefinition must not add, remove or rename fields or methods, change the
              signatures of methods, change modifiers, or change inheritance.
              The redefinition must not change the <code>NestHost</code>,
     -        <code>NestMembers</code>, or <code>Record</code> attributes.
     +        <code>NestMembers</code>, <code>Record</code>, or <code>PermittedSubclasses</code>
     +        attributes.
              These restrictions may be lifted in future versions.
              See the error return description below for information on error codes
              returned if an unsupported redefinition is attempted.