windows:IO#sysseek moves the read position relative to the current position with SEEK_CUR
windows:IO#sysseek moves the read position relative to the start with SEEK_SET
windows:IO#sysseek moves the read position relative to the end with SEEK_END
fails:IO#sysseek accepts the symbol :CUR for SEEK_CUR
fails:IO#sysseek accepts the symbol :SET for SEEK_SET
fails:IO#sysseek accepts the symbol :END for SEEK_END
