Bug#898947: Please backport "Use grub-file to figure out whether multiboot2 should be used for Xen.gz"

[Ian Jackson]

Package: grub2
Version: 2.02+dfsg1-4

I'm told that "multiboot" does not work with UEFI and "multiboot2" is
needed.  (Not sure if this is true only for Xen, or more generally.)
I'm also told that buster's grub has enough to support booting Xen,
although I have not verified this myself.

Therefore, please could you cherry pick this
  http://git.savannah.gnu.org/cgit/grub.git/commit/?id=b4d709b6ee789cdaf3fa7a80fd90c721a16f48c2
onto your next upload for buster ?

Thanks,
Ian.