pypy: Remove redundant manual building of CFFI extensions

This hardcoded list of CFFI extension modules gets stale when PyPy adds
more, but fortunately the main translation step already builds these now
(hack_for_cffi_modules in pypy/goal/targetpypystandalone.py).

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

pkgs/development/interpreters/python/pypy/2.7/default.nix

@@ -79,17 +79,6 @@ in stdenv.mkDerivation rec {
 
   setupHook = python-setup-hook sitePackages;
 
-  postBuild = ''
-    pushd ./lib_pypy
-    ../pypy-c ./_audioop_build.py
-    ../pypy-c ./_curses_build.py
-    ../pypy-c ./_pwdgrp_build.py
-    ../pypy-c ./_sqlite3_build.py
-    ../pypy-c ./_syslog_build.py
-    ../pypy-c ./_tkinter/tklib_build.py
-    popd
-  '';
-
   doCheck = true;
   checkPhase = ''
     export TERMINFO="${ncurses.out}/share/terminfo/";