t3902 - skip test if file system doesn't support HT in names

Windows / cygwin don't support HT, LF, or TAB in file name so this test
is meaningless there.

Signed-off-by: Mark Levedahl <mdl123@verizon.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t3902-quoted.sh

@@ -7,6 +7,12 @@ test_description='quoted output'
 
 . ./test-lib.sh
 
+P1='pathname	with HT'
+: >"$P1" 2>&1 && test -f "$P1" && rm -f "$P1" || {
+	echo >&2 'Filesystem does not support HT in names'
+	test_done
+}
+
 FN='濱野'
 GN='純'
 HT='	'