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.tests b/shell/ash_test/ash-signals/signal_read2.tests
new file mode 100755
index 0000000..eab5b9b
--- /dev/null
+++ b/shell/ash_test/ash-signals/signal_read2.tests
@@ -0,0 +1,7 @@
+$THIS_SH -c '
+(sleep 1; kill -HUP $$) &
+while true; do
+	read ignored
+done
+'
+echo "Done:$?"