AP_DAL: only enable standalone build with --no-gcs and --disable-scripting

libraries/AP_DAL/examples/AP_DAL_Standalone/main.cpp

@@ -52,20 +52,14 @@ public:
 AP_HAL_DAL_Standalone _hal;
 const AP_HAL::HAL &hal = _hal;
 
-#ifdef HAL_NO_GCS
 NavEKF2 navekf2;
 NavEKF3 navekf3;
-#endif
 
 int main(int argc, const char *argv[])
 {
-#ifdef HAL_NO_GCS
     navekf2.InitialiseFilter();
     navekf3.InitialiseFilter();
     navekf2.UpdateFilter();
     navekf3.UpdateFilter();
     return navekf2.healthy() && navekf3.healthy()?0:1;
-#else
-    return 0;
-#endif
 }

libraries/AP_DAL/examples/AP_DAL_Standalone/wscript

@@ -18,7 +18,9 @@ def build(bld):
         ],
     )
 
-    bld.ap_program(
-        program_groups=['tools'],
-        use='AP_DAL_libs',
-    )
+    # only valid to build with no GCS and no scripting
+    if '-DHAL_NO_GCS=1' in bld.env.CXXFLAGS and 'ENABLE_SCRIPTING=1' not in bld.env.DEFINES:
+        bld.ap_program(
+            program_groups=['tools'],
+            use='AP_DAL_libs',
+        )