[Pkg-rust-maintainers] rustc/cargo in stretch

[Julien Cristau]

Hi,

rustc and cargo in stretch have no reverse deps so far, are likely to be
needed at a newer version when firefox-esr updates to 59, and I'm
worried the current version is not going to be supportable as is.  So I
think we should remove both packages from stretch and avoid painting
ourselves into a corner.  Thoughts?

Cheers,
Julien