Use "Py_ssize_t" instead of "int" for a node counter variable to avoid...

Use "Py_ssize_t" instead of "int" for a node counter variable to avoid uselessly limiting its value range.

Cython/Compiler/Visitor.py

@@ -198,7 +198,7 @@ class TreeVisitor(object):
         return self._visitchildren(parent, attrs)
 
     @cython.final
-    @cython.locals(idx=int)
+    @cython.locals(idx=cython.Py_ssize_t)
     def _visitchildren(self, parent, attrs):
         """
         Visits the children of the given parent. If parent is None, returns