Python: Add tests cases with synthetic arguments

Author: yoff

python/ql/test/experimental/dataflow/consistency/dataflow-consistency.expected

@@ -1,4 +1,8 @@
 uniqueEnclosingCallable
+| test.py:239:27:239:27 | ControlFlowNode for p | Node should have one enclosing callable but has 0. |
+| test.py:245:5:245:22 | PosOverflowNode for overflowCallee() | Node should have one enclosing callable but has 0. |
+| test.py:248:5:248:26 | KwOverflowNode for overflowCallee() | Node should have one enclosing callable but has 0. |
+| test.py:251:5:251:33 | KwOverflowNode for overflowCallee() | Node should have one enclosing callable but has 0. |
 uniqueType
 uniqueNodeLocation
 missingLocation

python/ql/test/experimental/dataflow/consistency/test.py

@@ -235,3 +235,17 @@ def non_const_eq_preserves_taint(x):
         SINK(tainted) # unsafe
     if tainted == x:
         SINK(tainted) # unsafe
+
+def overflowCallee(*args, p="", **kwargs):
+    print("args", args)
+    print("p", p)
+    print("kwargs", kwargs)
+
+def synth_arg_posOverflow():
+    overflowCallee(42)
+
+def synth_arg_kwOverflow():
+    overflowCallee(foo=42)
+
+def synth_arg_kwUnpacked():
+    overflowCallee(**{"p": "42"})