t0001: skip test with restrictive permissions if getpwd(3) respects them

t0001: skip test with restrictive permissions if getpwd(3) respects them

The sub-test "init in long base path" in t0001 checks the ability to
handle long base paths with restrictive permissions (--x).  On OpenBSD
getcwd(3) fails in that case even for short paths.  Check the two
aspects separately by trying to use a long base path both with and
without execute-only permissions.  Only attempt the former if we know
that getcwd(3) doesn't care.

Original-patch-by: David Coppa <dcoppa@openbsd.org>
Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>