libbsd-freedesktop: re-init at 0.9.1, use for samba

a partial rollback of #41320

samba is already Linux-only because of acl, and it is unclear what the
problem is with upstream netbsd-compat.

pkgs/development/libraries/libbsd/default.nix

@@ -0,0 +1,21 @@
+{ stdenv, fetchurl }:
+
+stdenv.mkDerivation rec {
+  name = "libbsd-${version}";
+  version = "0.9.1";
+
+  src = fetchurl {
+    url = "http://libbsd.freedesktop.org/releases/${name}.tar.xz";
+    sha256 = "1957w2wi7iqar978qlfsm220dwywnrh5m58nrnn9zmi74ds3bn2n";
+  };
+
+  patches = [];
+
+  meta = with stdenv.lib; {
+    description = "Common functions found on BSD systems, Freedesktop fork";
+    homepage = https://libbsd.freedesktop.org/;
+    license = licenses.bsd3;
+    platforms = platforms.linux;
+    maintainers = with maintainers; [ raskin ];
+  };
+}

pkgs/top-level/all-packages.nix

@@ -12938,6 +12938,7 @@ with pkgs;
 
   samba4 = callPackage ../servers/samba/4.x.nix {
     python = python2;
+    libbsd = libbsd-freedesktop;
   };
 
   sambaMaster = callPackage ../servers/samba/master.nix { };
@@ -21491,6 +21492,8 @@ with pkgs;
 
   libbsd = netbsd.compat;
 
+  libbsd-freedesktop = callPackage ../development/libraries/libbsd {};
+
   inherit (recurseIntoAttrs (callPackages ../os-specific/bsd { }))
           netbsd;