Get some first extract_function stuff working

test/refactor/extract_function.py

@@ -0,0 +1,20 @@
+# -------------------------------------------------- in-module-1
+#? 11 text {'new_name': 'a'}
+test(100, (30 + b, c) + 1)
+# ++++++++++++++++++++++++++++++++++++++++++++++++++
+#? 11 text {'new_name': 'a'}
+def a():
+    return 30 + b
+
+
+test(100, (a(), c) + 1)
+# -------------------------------------------------- in-module-2
+#? 0 text {'new_name': 'ab'}
+100 + 1 * 2
+# ++++++++++++++++++++++++++++++++++++++++++++++++++
+#? 0 text {'new_name': 'ab'}
+def ab():
+    return 100 + 1 * 2
+
+
+ab()