add gsup_test to catch OS#3231
Encode an Insert Subscr Data with is_ps == true to trigger the encoding bug
described in OS#3231, i.e. show that it is fixed.
Move osmo_gsup_addr_send() to a separate .c file, so that it can be overridden
in the regression test to just dump the msgb instead.
I used this test to reproduce issue OS#3231, and now that it's here we might as
well keep it, and possibly expand on it in the future.
Related: OS#3231
Change-Id: Id1453351758f3e1a9ff03bd99fefaf51886e77da
diff --git a/tests/gsup/gsup_test.err b/tests/gsup/gsup_test.err
new file mode 100644
index 0000000..d9d272a
--- /dev/null
+++ b/tests/gsup/gsup_test.err
@@ -0,0 +1,2 @@
+DMAIN 10 01 08 21 43 65 87 09 21 43 f5 08 09 08 89 67 45 23 01 89 67 f5 05 07 10 01 01 12 02 01 2a
+DMAIN LU OP state change: LU RECEIVED -> ISD SENT