message: Fix incorrect rejection of xrange.
diff: @@ -49,7 +49,9 @@ class BuiltinFunctionTransformer(transformer.Base):
  def visit_Call(self, node):
  self.generic_visit(node)
  # TODO(mdan): This won't work if the function was hidden.
  - if isinstance(node.func, gast.Name) and node.func.id in ('len', 'range'):
  + # TODO(mdan): Rely on the live_val and use inspect_utils.is_builtin instead.
  + if (isinstance(node.func, gast.Name) and
  + node.func.id in ('len', 'range', 'xrange')):
  return self._convert_builtin(node)
  # Print needs to be handled separately because it can be read as statement.
  if isinstance(node.func, gast.Name) and node.func.id == 'print':
  