cobol: Add POSIX tests gcc/testsuite/ChangeLog: * cobol.dg/group2/Hello.cob: New test. * cobol.dg/group2/Hello.out: New test. * cobol.dg/group2/Read_and_write_errno.cob: New test. * cobol.dg/group2/Read_and_write_errno.out: New test.