ash testsuite: update some of variable tests with newer versions from hush

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

shell/ash_test/ash-vars/var_bash5.tests

@@ -4,8 +4,26 @@
 v='a/b/c'
 s='b/c'
 r='e/f'
-echo "${v/$s}"
-echo "${v/$s/d}"
-echo "${v/$s/$r}"
+echo "1 ${v/$s}"
+echo "2 ${v/$s/d}"
+echo "3 ${v/$s/$r}"
+
+v='a\b\c'
+s='b\\c'
+r='e\f'
+echo "4 ${v/$s}"
+echo "5 ${v/$s/d}"
+echo "6 ${v/$s/$r}"
+
+v='a\\b\\c'
+s='b\\\\c'
+r='e\\f'
+echo "7 ${v/$s}"
+echo "8 ${v/$s/d}"
+echo "9 ${v/$s/$r}"
+
+v='a-$a-\t-\\-\"-\`-\--\z-\*-\?-b'
+s='-$a-\\t-\\\\-\\"-\\`-\\--\\z-\\\*-\\\?-'
+echo "a ${v/$s}"
 
 echo Done: $?