Move f_addrstr2addr() to library/Misc_Helpers.ttcn

This function can easily be reused in other testsuites supporting both
IPv4 and IPv6 addresses.

Change-Id: I4243ec5551f128629b6504ccc59efeb456a6855d
diff --git a/library/Misc_Helpers.ttcn b/library/Misc_Helpers.ttcn
index e01c170..dda2c2c 100644
--- a/library/Misc_Helpers.ttcn
+++ b/library/Misc_Helpers.ttcn
@@ -1,5 +1,7 @@
 module Misc_Helpers {
 
+import from Native_Functions all;
+
 modulepar {
 	charstring mp_osmo_repo := "nightly";
 }
@@ -51,4 +53,12 @@
 	return false;
 }
 
+function f_addrstr2addr(charstring addr) return octetstring {
+	if (f_addr_is_ipv6(addr)) {
+		return f_inet6_addr(addr);
+	} else {
+		return f_inet_addr(addr);
+	}
+}
+
 }