t4135-*.sh: Skip the "backslash" tests on cygwin
t4135-*.sh: Skip the "backslash" tests on cygwin

The BSLASHPSPEC tests (11-13) fail on cygwin, since you can't
create files containing an backslash character in the name.
In order to skip these tests, we simply stop (incorrectly)
asserting the BSLASHPSPEC prerequisite in test-lib.sh.

Signed-off-by: Ramsay Jones <3e74413778ce9c8bebbbaedfd56741f6850faeaf@ramsay1.demon.co.uk>
Acked-by: Johannes Sixt <fd432345609ae4d58c1aa629cb66ba96d1391622@kdbg.org>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git