msc: move f_gen_{imei,imsi,msisdn} to L3_Templates.ttcn

This allows them to be reused in upcoming SGSN tests.

Change-Id: I0459eeb44e58342da656f2312560466698374b72
diff --git a/library/L3_Templates.ttcn b/library/L3_Templates.ttcn
index a3db409..76725fc 100644
--- a/library/L3_Templates.ttcn
+++ b/library/L3_Templates.ttcn
@@ -1472,5 +1472,26 @@
 	}
 }
 
+private function f_concat_pad(integer tot_len, hexstring prefix, integer suffix) return hexstring {
+	var integer suffix_len := tot_len - lengthof(prefix);
+	var charstring suffix_ch := int2str(suffix);
+	var integer pad_len := suffix_len - lengthof(suffix_ch);
+
+	return prefix & int2hex(0, pad_len) & str2hex(suffix_ch);
+}
+
+function f_gen_imei(integer suffix) return hexstring {
+	return f_concat_pad(15, '49999'H, suffix);
+}
+
+function f_gen_imsi(integer suffix) return hexstring {
+	return f_concat_pad(15, '26242'H, suffix);
+}
+
+function f_gen_msisdn(integer suffix) return hexstring {
+	return f_concat_pad(12, '49123'H, suffix);
+}
+
+
 
 }