[Mesa-stable] Nominate commit 29283921b72fa9386322fc9eb301d00e88b634b6 for all stable branches

[Emil Velikov]

Hi all,

I think we'd want the following commit for stable.
It doesn't "fix" anything per se, but removes hundreds of warning messages.

commit 29283921b72fa9386322fc9eb301d00e88b634b6 (HEAD -> master,
origin/master, origin/HEAD)
Author: Emil Velikov <emil.velikov at collabora.com>
Date:   Wed Oct 24 18:53:11 2018 +0100

   m4: add Werror when checking for compiler flags

-Emil
P.S. Shout-out to Eric for suggesting it