library/GSM_RR_Types: add minimalistic AssignmentCommand

Unfortunately, the existing implementation [1] is somewhat
incomplete and unfriendly to build templates on:

  - some fields holding integer numbers defined as BITx,
    so we would have to do bit2int() / int2bit();

  - some bit-map fields defined as octetstrings;

  - some fields are not decoded at all (raw octetstrings).

Let's work this around by defining a minimalistic implementation
of (RR) Assignment Command with all mandatory and some optional
fields.  Reuse some IEs directly from MobileL3_RRM_Types.

[1] titan.ProtocolModules.MobileL3_v13.4.0
    MobileL3_RRM_Types.PDU_RRM_AssignmentCommand_NW_MS

Change-Id: If1a5244a688abed6e6de2bf3f6e19e0e28129ea5
Related: SYS#4868, OS#4545
diff --git a/sysinfo/gen_links.sh b/sysinfo/gen_links.sh
index 0648e7b..fa3cd33 100755
--- a/sysinfo/gen_links.sh
+++ b/sysinfo/gen_links.sh
@@ -9,7 +9,7 @@
 gen_links $DIR $FILES
 
 DIR=$BASEDIR/titan.ProtocolModules.MobileL3_v13.4.0/src
-FILES="MobileL3_CommonIE_Types.ttcn MobileL3_GMM_SM_Types.ttcn MobileL3_MM_Types.ttcn"
+FILES="MobileL3_CommonIE_Types.ttcn MobileL3_GMM_SM_Types.ttcn MobileL3_MM_Types.ttcn MobileL3_RRM_Types.ttcn"
 gen_links $DIR $FILES
 
 DIR=$BASEDIR/titan.TestPorts.Common_Components.Socket-API/src