Improve test to allow easier understanding of errors

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24516 3ad0048d-3df7-0310-abae-a5850022a9f2
 Avoid some range check errors for msdos target

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24517 3ad0048d-3df7-0310-abae-a5850022a9f2