Make a test work in Py3.7 that changed behaviour in Python 3.7...

Make a test work in Py3.7 that changed behaviour in Python 3.7 ("generator_stop" future import became active by default).

tests/run/generators_py.py

@@ -81,17 +81,6 @@ def with_outer(*args):
             yield i
     return generator
 
-def with_outer_raising(*args):
-    """
-    >>> x = with_outer_raising(1, 2, 3)
-    >>> list(x())
-    [1, 2, 3]
-    """
-    def generator():
-        for i in args:
-            yield i
-        raise StopIteration
-    return generator
 
 def test_close():
     """

tests/run/generators_py35.py

+# mode: run
+# tag: generators, pure3.5
+
+from __future__ import generator_stop
+
+# "generator_stop" was only added in Py3.5.
+
+
+def with_outer_raising(*args):
+    """
+    >>> x = with_outer_raising(1, 2, 3)
+    >>> try:
+    ...     list(x())
+    ... except RuntimeError:
+    ...     print("OK!")
+    ... else:
+    ...     print("NOT RAISED!")
+    OK!
+    """
+    def generator():
+        for i in args:
+            yield i
+        raise StopIteration
+    return generator