Bug#792657: ocaml-ctypes: needs update to ctypes 0.4

[whitequark <whitequark@whitequark.org>]

Source: ocaml-ctypes
Severity: normal

Dear Maintainer,

Please update the ctypes package to 0.4. LLVM OCaml bindings require
ctypes >=0.4 to enable their full functionality since 3.7, and due
to ctypes being outdated these are currently not built for Debian.

Due to an upstream bug, LLVM 3.6 also requires ctypes, but with
a version constraint of >=0.3 <0.4. I am not sure how important
would it be to package that.

-- System Information:
Debian Release: stretch/sid
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'unstable'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.0.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)