* fix breakage of the OS/2 RTL

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@25190 3ad0048d-3df7-0310-abae-a5850022a9f2
* use Tai_const.Create_nil_dataptr instead of Tai_const.Create_sym(nil) when writing nil for the parent vmt pointer

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@25191 3ad0048d-3df7-0310-abae-a5850022a9f2