chore: add simple iw3 system test

test/SystemTests.lua

@@ -44,6 +44,8 @@ function SystemTests:project()
         ObjLoading:include(includes)
         ObjCompiling:include(includes)
         ObjWriting:include(includes)
+        Linking:include(includes)
+        Unlinking:include(includes)
 		catch2:include(includes)
 
 		Raw:use()
@@ -56,5 +58,7 @@ function SystemTests:project()
 		links:linkto(ObjWriting)
 		links:linkto(catch2)
 		links:linkto(Catch2Common)
+		links:linkto(Linking)
+		links:linkto(Unlinking)
 		links:linkall()
 end