Release 8.0.1 (finally!)

Adjust error check for class method types

Fixes Trac #11793.  Nothing deep here.

(cherry picked from commit e24b3b1)

Deriving Functor-like classes should unify kind variables

While the deriving machinery always unifies the kind of the typeclass
argument with the kind of the datatype, this proves not to be sufficient
to produce well kinded instances for some poly-kinded datatypes. For
example:

```
newtype Compose (f :: k2 -> *) (g :: k1 -> k2) (a :: k1)
  = Compose (f (g a)) deriving Functor
```

would fail because only `k1` would get unified with `*`, causing the
following
ill kinded instance to be generated:

```
instance (Functor (f :: k2 -> *), Functor (g :: * -> k2)) =>
  Functor (Compose f g) where ...
```

To prevent this, we need to take the subtypes and unify their kinds with
`* -> *`.

Fixes #10524 for good.

Test Plan: ./validate

Reviewers: simonpj, hvr, austin, bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2097

GHC Trac Issues: #10524, #10561

(cherry picked from commit aadde2b)

Bump Cabal submodule

configure.ac: Bump down version number

To ensure that the release candidate version has the correct
lexicographic relation to the release.

Start of GHC 8.1 development branch

(This annotated tag helps tools such as `git describe`)

Release 7.103a

This is a patchlevel release over 7.10.3 which fixes a few
documentation issues.

Release version 7.10.3

x86 codegen: don't generate location comments

The following source snippet 'module A where x */* y = 42'
when being compiled with '-g' option emits syntactically
invalid comment for GNU as:

    .text
        .align 8
        .loc 1 3 1 /* */* */

Fixed by not emitting comments at all. We already suppress
all asm comments in 'X86/Ppr.hs'.

Signed-off-by: Sergei Trofimovich <[email protected]>

Test Plan: added test and check it works

Reviewers: scpmw, simonmar, austin, bgamari

Reviewed By: simonmar

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1386

GHC Trac Issues: #10667

aclocal.m4: Do not check for readelf on darwin

Tested on darwin and linux. Not tested on mingw32.