Python: Add return (func_ref, ...) test

Author: RasmusWL

python/ql/test/experimental/library-tests/CallGraph/InlineCallGraphTest.expected

@@ -17,6 +17,7 @@ pointsTo_found_typeTracker_notFound
 | code/funky_regression.py:15:9:15:17 | ControlFlowNode for Attribute() | Wat.f2 |
 | code/runtime_decision.py:44:1:44:7 | ControlFlowNode for func4() | "code/runtime_decision_defns.py:4:func4" |
 | code/runtime_decision.py:44:1:44:7 | ControlFlowNode for func4() | "code/runtime_decision_defns.py:7:func4" |
+| code/tuple_function_return.py:15:1:15:4 | ControlFlowNode for f2() | func |
 | code/type_tracking_limitation.py:8:1:8:3 | ControlFlowNode for x() | my_func |
 typeTracker_found_pointsTo_notFound
 | code/callable_as_argument.py:29:5:29:12 | ControlFlowNode for Attribute() | test_class.InsideTestFunc.sm |

python/ql/test/experimental/library-tests/CallGraph/code/tuple_function_return.py

@@ -0,0 +1,15 @@
+def func():
+    print("func()")
+
+def return_func():
+    return func
+
+def return_func_in_tuple():
+    return (func, 42)
+
+f1 = return_func() # $ pt,tt=return_func
+f1() # $ pt,tt=func
+
+
+f2, _ = return_func_in_tuple() # $ pt,tt=return_func_in_tuple
+f2() # $ pt=func MISSING: tt