base: Fix documentation for forkIOWithUnmask

forkIOUnmasked has been deprecated for several years now. Update reference to
it. See #4858 and #5546.

(cherry picked from commit 1840121)

Revert "Make raiseIO# produce topRes"

This reverts commit da4687f.

It's not entirely trivial to clean up the dead code this patch
introduced. In particular, when we see

```
case raiseIO# m s of
  s' -> e
```

we want to know that `e` is dead. For scrutinees that are properly
bottom (which we don't want to consider `raiseIO# m s` to be, this
is handled by rewriting `bot` to `case bot of {}`. But if we do
that for `raiseIO#`, we end up with

```
case raiseIO# m s of {}
```

which looks a lot like bottom and could confuse demand analysis.
I think we need to wait with this change until we have a more
complete story.

Reviewers: austin, bgamari

Reviewed By: bgamari

Subscribers: rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D3413

(cherry picked from commit e83af07)

Start of GHC 8.3 development branch

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

Release 8.0.2 (at long last!)

Release 8.0.2-rc2

Remove fancy shadowing logic; always override in package database order.

This is a stopgap fix for GHC 8.0 bug #12485: in particular,
it relaxes need for -package-db flags to be given in
dependency order.  The trade-off is that we are a lot more
unsafe when there are packages with duplicate 'id's in
the database stack: the new code will not do an ABI compatibility
check: if two packages have the same 'id', they are assumed to
be ABI compatible.  If this is not true, GHC may build
segfaulting executables.

Missing test updates, but I'm putting it up so people can
take a look.

In GHC 8.2, we'll record ABIs for all dependencies, allowing
GHC to make better decisions about shadowing.

Signed-off-by: Edward Z. Yang <[email protected]>

Test Plan: validate

Reviewers: austin, niteria, bgamari, simonmar

Reviewed By: simonmar

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2613

GHC Trac Issues: #12485

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