z3: move to multiple output packages

The Z3 source code is effectively compiled into two completely separate
objects: the z3 binary file, and the libz3.so library -- but the binary is not
linked against the shared library, it simply incorporates all of the object
files. The Z3 code base results in an ~25MB object on x86_64-linux. As a
result, splitting bin/ and lib/ results in a 50% reduction in closure size.

(The include/ directory is also surprisingly large at .5MB...)

This also splits the python API into a completely separate .python attribute,
as well.

Signed-off-by: Austin Seipp <aseipp@pobox.com>

pkgs/applications/science/logic/z3/default.nix

@@ -20,6 +20,20 @@ stdenv.mkDerivation rec {
     cd build
   '';
 
+  postInstall = ''
+    mkdir -p $dev $lib $python/lib
+
+    mv $out/lib/python*  $python/lib/
+    mv $out/lib          $lib/lib
+    mv $out/include      $dev/include
+
+    # clean up a copy of libz3.so and symlink it instead
+    rm $python/${python.sitePackages}/z3/lib/libz3.so
+    ln -s $lib/lib/libz3.so $python/${python.sitePackages}/z3/lib/libz3.so
+  '';
+
+  outputs = [ "out" "lib" "dev" "python" ];
+
   meta = {
     description = "A high-performance theorem prover and SMT solver";
     homepage    = "https://github.com/Z3Prover/z3";