AP_HAL_SITL: Added Software simulation for Advanced Navigation Devices.

Adds ability for SITL Simulation of an AdNav device to be used by making a simulated serial port.
Changes create a SITL::AdNav class when requested on the command line

libraries/AP_HAL_SITL/SITL_State_common.cpp

@@ -269,6 +269,12 @@ SITL::SerialDevice *SITL_State_Common::create_serial_sim(const char *name, const
         }
         microstrain5 = new SITL::MicroStrain5();
         return microstrain5;
+    } else if (streq(name, "AdNav")) {
+        if (adnav != nullptr) {
+            AP_HAL::panic("Only one AdNav at a time");
+        }
+        adnav = new SITL::AdNav();
+        return adnav;
 #if HAL_SIM_AIS_ENABLED
     } else if (streq(name, "AIS")) {
         if (ais != nullptr) {
@@ -435,6 +441,10 @@ void SITL_State_Common::sim_update(void)
         microstrain5->update();
     }
 
+    if (adnav != nullptr) {
+        adnav->update();
+    }
+
 #if HAL_SIM_AIS_ENABLED
     if (ais != nullptr) {
         ais->update();

libraries/AP_HAL_SITL/SITL_State_common.h

@@ -34,6 +34,7 @@
 #include <SITL/SIM_RF_GYUS42v2.h>
 #include <SITL/SIM_VectorNav.h>
 #include <SITL/SIM_MicroStrain.h>
+#include <SITL/SIM_AdNav.h>
 #include <SITL/SIM_AIS.h>
 #include <SITL/SIM_GPS.h>
 
@@ -200,6 +201,9 @@ class HALSITL::SITL_State_Common {
     // simulated LORD MicroStrain system
     SITL::MicroStrain5 *microstrain5;
 
+    // simulated AdNav system:
+    SITL::AdNav *adnav;
+
 #if HAL_SIM_JSON_MASTER_ENABLED
     // Ride along instances via JSON SITL backend
     SITL::JSON_Master ride_along;