Bootstrapping 7.8 using 7.10

[Yitzchak Gale]

Moving here from Reddit, as suggested by Herbert.
This a continuation of a thread that started with
Edward Yang's post here:

http://mail.haskell.org/pipermail/glasgow-haskell-users/2014-October/025389.html

continued here, a few months later:

http://mail.haskell.org/pipermail/glasgow-haskell-users/2014-December/025529.html

and ended here, in the following month:

http://mail.haskell.org/pipermail/glasgow-haskell-users/2015-January/025551.html

Herbert Valerio Riedel wrote on Reddit
(http://www.reddit.com/r/haskell/comments/2zc2jg/ghc_7101_rc3_is_out_test_it_while_its_fresh/cpindvt)

> I think I remember what the problem was with your patch (and why it
> wasn't picked up rightaway): you needed tweaks to boot packages such
> as transformers would cause the GHC source-tarball to diverge from
> the officially released upstream packages. One solution would be to
> rather provide an out-of-tree patch a user can apply manually,
> rather than making an official GHC 7.8.5 release with unofficial
> modifications to upstream packages (which would also require some
> administration overhead on the Git level as upstream packages are
> automatically mirrored Git submodules).

I think Edward's last post (in January, linked above) addressed those
concerns. In summary: release upstream point releases for hpc and
hoopl that only bump the dependencies of base and time, and provide
instance Applicative IO in the GHC sources for 7.8.5 so that no change
is needed for transformers.

Will that work? Can we go with this?

Thanks,
Yitz