Disable test not relevant for Python -builtin

Examples/test-suite/python/python_append_runme.py

@@ -1,11 +1,16 @@
 from python_append import *
+
+# test not relevant for -builtin
+if is_python_builtin():
+  exit(0)
+
 t=Test()
 t.func()
 t.static_func()
 
 if grabpath() != os.path.dirname(mypath):
-  raise RuntimeError
+  raise RuntimeError("grabpath failed")
 
 if grabstaticpath() != os.path.basename(mypath):
-  raise RuntimeError
+  raise RuntimeError("grabstaticpath failed")
 

Examples/test-suite/python_append.i

@@ -46,5 +46,10 @@ public:
   void func() {};
 };
 
+#ifdef SWIGPYTHON_BUILTIN
+bool is_python_builtin() { return true; }
+#else
+bool is_python_builtin() { return false; }
+#endif
 %}