https://github.com/ocamllabs/ocaml-ctypes/blob/0.18.0/CHANGES.md#ctypes-0180
* ocamlPackages.async_ssl: fix compatibility with ctypes 0.18.0 by using
ctypes.foreign instead of ctypes.foreign.threaded since the distinction
between threaded and unthreaded has been removed in this release.
* libbap: link with -thread so linking ctypes.foreign doesn't fail
https://github.com/BinaryAnalysisPlatform/bap-bindings/issues/18
* ocaml-ng.ocamlPackages_4_07.sodium: patch lib_gen/_tags to also add
the `package(bigarray)` directive since `ctypes.stubs` no longer
propgates that, leading to module not found error.
* ocaml-ng.ocamlPackages_4_{04,05,06,07}.async_ssl: mark as broken: due to
the bigarray-compat dependency, we need dune 2 for ctypes which breaks
compilation of the legacy async_ssl 0.11 version since we can't
upgrade to dune 2 for it since that version doesn't support the legacy
jbuild files.
continuation of #109595
pkgconfig was aliased in 2018, however, it remained in
all-packages.nix due to its wide usage. This cleans
up the remaining references to pkgs.pkgsconfig and
moves the entry to aliases.nix.
python3Packages.pkgconfig remained unchanged because
it's the canonical name of the upstream package
on pypi.