bts: Extend LAPDm test suite with a number of new tests

This adds the following test cases to BTS_Tests_LAPDm.ttcn:
* TC_sabm_retransmit_bts()
* TC_sabm_invalid_resp()
* TC_sabm_dm()
* TC_establish_ign_first_sabm()
* TC_iframe_seq_and_ack()
* TC_iframe_timer_recovery()

Change-Id: I4e1136c0c0f10d5bc8d01e826ae5d92f17a0b2aa
diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index c43774d..e48c05a 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -61,9 +61,11 @@
 
 import from Osmocom_VTY_Functions all;
 import from TELNETasp_PortType all;
+import from BTS_Tests_LAPDm all;
 
 friend module BTS_Tests_SMSCB;
 friend module BTS_Tests_virtphy;
+friend module BTS_Tests_LAPDm;
 
 /* The tests assume a BTS with the following timeslot configuration:
  * TS0 : Combined CCCH + SDCCH/4
@@ -155,7 +157,7 @@
 }
 
 /* an individual call / channel */
-type component ConnHdlr extends RSL_DchanHdlr {
+type component ConnHdlr extends RSL_DchanHdlr, lapdm_test_CT {
 	port L1CTL_PT L1CTL;
 
 	port TRXC_CODEC_PT BTS_TRXC;
@@ -551,7 +553,7 @@
 			"RF CHAN REL", true);
 }
 
-private template ConnHdlrPars t_Pars(template RslChannelNr chan_nr,
+friend template ConnHdlrPars t_Pars(template RslChannelNr chan_nr,
 					template RSL_IE_ChannelMode chan_mode,
 					float t_guard := 20.0) := {
 	chan_nr := valueof(chan_nr),
@@ -699,7 +701,7 @@
 }
 
 /* execute the same callback function on a variety of logical channels */
-private function f_testmatrix_each_chan(ConnHdlrPars pars, void_fn fn) runs on test_CT {
+friend function f_testmatrix_each_chan(ConnHdlrPars pars, void_fn fn) runs on test_CT {
 	var ConnHdlr vc_conn;
 	f_init();