This adds tests where an untracked file and an untracked symlink are in the
way where a directory should be created by 'git checkout'. Commit b1735b1a
(do not overwrite files in leading path, 2010-12-14) fixed the case where
a file is in the way, but the untracked symlink is still removed silently.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>