sbcl: 2.0.1 -> 2.0.2

Current, the `cabal2nix` derivation contains both the executable, and a wrapper
that adds `nix` and `nix-prefetch-scripts`, which are required for some
features.

However, when calling `callCabal2nix` to create a derivation from a cabal file
at evaluation time,
these features are not actually used, but the huge closure of
`nix-prefetch-scripts` (which includes multiple vcs, as well as python and perl)
still needs to be fetched.

This commit splits cabal2nix into a lightweight version that is a standalone
static binary (`cabal2nix-unwrapped`), and a wrapper that includes the proper
dependencies in the path for full usage of the command line
utility (`cabal2nix`).

This commit also switches to the default ghc, to reduce the likelyhood of
building a different ghc when calling `callCabal2nix`.

The tests fail to compile because of a missing module but would
otherwise be fine.

tests need a running mysql instance, so disable them

Signed-off-by: Anders Kaseorg <andersk@mit.edu>

This update was generated by hackage2nix v2.15.0-21-ga388e13 from Hackage revision
commercialhaskell/all-cabal-hashes@a155538.

The package doesn't have a testsuite, but fails as the checkPhase is
missing appropriate locale configuration (usually taken from
`pkgs.glibcLocales`). Entirely disabling the `checkPhase` for now as
it's basically a no-op.

ZHF: #80379
See also https://hydra.nixos.org/build/114125176

Update Haskell package set to LTS 15.3 (plus other fixes)

vaultenv: 0.13.0 -> 0.13.1

These patches are gathered from different sources,
such as https://patchwork.kernel.org/patch/10862231/ for the
`gettid` patch.
Another patch comes from the issue in the AFL repository.
The ultimate goal is to get these patches upstream as well,
so we don't keep these general patches only within nixos.

A PR is created against Google/AFL
google/AFL#79,
but it might take a while before it's landed, considering the history
of the project (there are more PRs open).

ZHF: #80379

Fixes issue #82232

This is a bugfix release.

See https://lists.gnu.org/archive/html/info-gnu/2020-03/msg00007.html
for details.

...even when networkd is disabled

This reverts commit ce78f3a, reversing
changes made to dc34da0.

I'm sorry; Hydra has been unable to evaluate, always returning
> error: unexpected EOF reading a line
and I've been unable to reproduce the problem locally.  Bisecting
pointed to this merge, but I still can't see what exactly was wrong.