ash: copy three tests from hush_test/hush-signals/*

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash_test/ash-signals/signal_read2.right b/shell/ash_test/ash-signals/signal_read2.right
new file mode 100644
index 0000000..87d8da3
--- /dev/null
+++ b/shell/ash_test/ash-signals/signal_read2.right
@@ -0,0 +1,2 @@
+Hangup
+Done:129