message: Internal cleanup: avoid discarding the result of NodeTransformer visitor, for consistency. This is a no-op, because generic_visit doesn't ever replace the node, so the CL is purely for consistency.
diff: @@ -347,7 +347,7 @@ class ControlFlowTransformer(converter.Base):
  return loop_vars, loop_vars_ast_tuple
  def visit_While(self, node):
  - self.generic_visit(node)
  + node = self.generic_visit(node)
  (basic_loop_vars, composite_loop_vars, reserved_symbols,
  possibly_undefs) = self._get_loop_vars(
  @@ -419,7 +419,7 @@ class ControlFlowTransformer(converter.Base):
  return undefined_assigns + node
  def visit_For(self, node):
  - self.generic_visit(node)
  + node = self.generic_visit(node)
  (basic_loop_vars, composite_loop_vars,
  reserved_symbols, possibly_undefs) = self._get_loop_vars(
  