[Swan-commit] Changes to ref refs/heads/master

[Andrew Cagney]

New commits:
commit 0133513e48b1d1371d5d508d22c4655d279fd4bd
Author: Andrew Cagney <cagney at gnu.org>
Date:   Sat Jun 13 14:52:37 2020 -0400

    ip: add address_mask_to_subnet(), use, test