Make tests public. Rewrite most tests. Add tests.

[pintos-anon] / src / tests / filesys / extended / dir-rm-root.ck

# -*- perl -*-
use strict;
use warnings;
use tests::tests;
check_expected (IGNORE_EXIT_CODES => 1, [<<'EOF']);
(dir-rm-root) begin
(dir-rm-root) remove "/" (must return false)
(dir-rm-root) create "/a"
(dir-rm-root) end
EOF