Bug#892397: grub2: build-depends on GCC 6

[pochu at debian.org]

Source: grub2
Severity: serious
Tags: sid buster
User: debian-gcc at lists.debian.org
Usertags: gcc-6-rm

Hi,

grub2 build-depends on GCC 6. We now have GCC 7 (default) and GCC 8
in the archive, so please make your package build with a newer
compiler (preferably the default one) again, since we'd like to
remove GCC 6 from testing before the buster release.

Cheers, Emilio