Suppress non-set result warning in Seek method

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@29106 3ad0048d-3df7-0310-abae-a5850022a9f2
 Suppress deprecated cmdline warning

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@29107 3ad0048d-3df7-0310-abae-a5850022a9f2
 Change z_verbose from const to typed const to avoid unreachable code warning

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@29108 3ad0048d-3df7-0310-abae-a5850022a9f2