ash: add two testcases for (not yet fixed) ash bugs

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash_test/ash-signals/signal5.tests b/shell/ash_test/ash-signals/signal5.tests
new file mode 100755
index 0000000..b75b149
--- /dev/null
+++ b/shell/ash_test/ash-signals/signal5.tests
@@ -0,0 +1,14 @@
+# Not fixed yet
+trap "echo USR1 received" USR1
+stub() {
+    echo "sleeping for $1 sec"
+    sleep $1
+    echo "$1 sec passed, sending USR1 to parent"
+    kill -USR1 $$
+}
+stub 2 &
+stub 1 &
+until { echo "Waiting"; wait; } do
+    echo "Wait exit code: $?"
+done
+echo "Wait returned 0"