Python: Add testfile with regressions

Author: yoff

python/ql/test/experimental/dataflow/regression/pointsto.expected

@@ -0,0 +1 @@
+| pointsto_regressions.py:15:18:15:21 | ControlFlowNode for self | pointsto_regressions.py:19:9:19:12 | ControlFlowNode for self |

python/ql/test/experimental/dataflow/regression/pointsto_regressions.py

@@ -0,0 +1,19 @@
+# This file contains snippets from snapshots that displayed interesting results for `pointsto.ql`.
+
+class Chatbot:
+    """
+    Main class which launch the training or testing mode
+    """
+
+    class TestMode:
+        """ Simple structure representing the different testing modes
+        """
+        ALL = 'all'
+        INTERACTIVE = 'interactive'  # The user can write his own questions
+        DAEMON = 'daemon'  # The chatbot runs on background and can regularly be called to predict something
+
+    def __init__(self):
+        """
+        """
+        # Model/dataset parameters
+        self.args = None