+ added segment _null, belonging to group dgroup and class BEGDATA with the
  hexadecimal pattern 01 in order to help catch storing data at location 0
  (this is compatible with Open Watcom's C library)



git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@26866 3ad0048d-3df7-0310-abae-a5850022a9f2