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

[Andrew Cagney]

New commits:
commit 9533e143082f480bee9eb6d9890796625e9283e6
Author: Andrew Cagney <cagney at gnu.org>
Date:   Sat May 30 12:27:22 2020 -0400

    building: always use += when adding to USERLAND_*FLAGS
    
    so mk/defaults/*.mk can prime it