Satisfying build-deps in testing

[Loïc Minier <lool+debian@via.ecp.fr>]

        Hi,

 I think build-deps currenlty only need to be satisfied in sid, but they
 might need to be satisfied in testing too at a later time in the
 release cycle, is this correct?

 I ask because of gnome-games which had a versionned build-dep on
 binutils (because it used --as-needed), and currently a fixed binutils
 exist for all arches in unstable, but can't migrate to testing due to
 FTBFSes.  The gnome-games is in the "dep-wait" state, and I asked
 buildd maintainers to reset that state;  Robert Bihlmeyer requested in
 #334491 to reinstate that build-dep.

 Hence, I need to clear that issue both for closing #334491 and to
 convince the mips/mipsel buildd maintainers.

 Please note that other packages than gnome-games have been uploaded
 with --as-needed, without the build-dep, and probably reached testing.

   Cheers,

-- 
Loïc Minier <lool@dooz.org>