Ensure that legacy code does not unnecessarily interfere with ARC.

rtl/inc/objpas.inc, TObject:
  * Free: don't call Destroy if the class is reference counted (there might be references left)


git-svn-id: http://svn.freepascal.org/svn/fpc/branches/svenbarth@28912 3ad0048d-3df7-0310-abae-a5850022a9f2