Python: add test for crosstalk

Author: yoff

python/ql/test/library-tests/ApiGraphs/py3/test_crosstalk.expected

@@ -0,0 +1,4 @@
+| test_crosstalk.py:8:16:8:18 | ControlFlowNode for f() | bar |
+| test_crosstalk.py:8:16:8:18 | ControlFlowNode for f() | baz |
+| test_crosstalk.py:13:16:13:18 | ControlFlowNode for g() | bar |
+| test_crosstalk.py:13:16:13:18 | ControlFlowNode for g() | baz |

python/ql/test/library-tests/ApiGraphs/py3/test_crosstalk.py

@@ -0,0 +1,13 @@
+
+def outer():
+    from foo import bar, baz
+    
+    def inner_bar():
+        f = bar
+        g = baz
+        return f()
+    
+    def inner_baz():
+        f = bar
+        g = baz
+        return g()

python/ql/test/library-tests/ApiGraphs/py3/test_crosstalk.ql

@@ -0,0 +1,8 @@
+import python
+import semmle.python.ApiGraphs
+
+from API::CallNode callNode, string member
+where
+  callNode = API::moduleImport("foo").getMember(member).getACall() and
+  callNode.getLocation().getFile().getBaseName() = "test_crosstalk.py"
+select callNode, member