testsuite: Fix location of typing_stubs module

This should fix the build on Debian 8.

typing_stubs.py → testsuite/driver/typing_stubs.py

 # Stub definitions for things provided by the typing package
 # for use by older Python versions.
 
+import collections
+
 class Dummy:
-    def __index__(self, *args):
+    def __getitem__(self, *args):
         return None
 
 List = Dummy()
@@ -10,4 +12,12 @@ Tuple = Dummy()
 Set = Dummy()
 TextIO = Dummy()
 Iterator = Dummy()
-Newtype = lambda name, ty: ty
+Callable = Dummy()
+Optional = Dummy()
+Dict = Dummy()
+Union = Dummy()
+Any = Dummy()
+
+NewType = lambda name, ty: ty
+def NamedTuple(name, fields):
+    return collections.namedtuple(name, [field[0] for field in fields])