tests/basics/fun_kwargs_syntax: Added a nested call test.

tests/basics/fun_kwargs_syntax.py

@@ -16,3 +16,4 @@ test_syntax("f(a or b=2)")
 test_syntax("f(2, (a)=3)")
 test_syntax("f((a) = 1, (b) = 5)")
 test_syntax("f((a, b) = 1)")
+test_syntax("f(f(), (a)=2)")