zlib: collapse library symlinks

overlay/default.nix

@@ -95,4 +95,12 @@ in {
 
   tup = prev.tup.overrideAttrs (attrs: { setupHook = ./tup/setup-hook.sh; });
 
+  zlib = overrideHostAttrs zlib (attrs: {
+    postInstall = attrs.postInstall or "" + ''
+      pushd ''${!outputLib}/lib
+      find . -type l -delete
+      mv libz.so.* libz.so
+      popd
+    '';
+  });
 }