tests: add oldselect.test

* tests/oldselect.c: New file.
* tests/oldselect.expected: Likewise.
* tests/oldselect.test: New test.
* tests/Makefile.am (check_PROGRAMS): Add oldselect.
(TESTS): Add oldselect.test.
(EXTRA_DIST): Add oldselect.expected.
* tests/.gitignore: Add oldselect.
diff --git a/tests/.gitignore b/tests/.gitignore
index 51d8dd2..801acee 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -18,6 +18,7 @@
 net-accept-connect
 netlink_inet_diag
 netlink_unix_diag
+oldselect
 pc
 pipe
 sched_xetattr