gobject-introspection: fix build on darwin

* add otool expression (add otool to build inputs)
* add libintlOrEmpty to build inputs

pkgs/development/tools/misc/otool/default.nix

@@ -0,0 +1,31 @@
+{ stdenv }:
+
+stdenv.mkDerivation {
+  name = "otool";
+
+  src = "/usr/bin/otool";
+
+  unpackPhase = "true";
+  configurePhase = "true";
+  buildPhase = "true";
+
+  installPhase = ''
+    mkdir -p "$out/bin"
+    cp /usr/bin/otool "$out/bin"
+  '';
+
+  meta = with stdenv.lib; {
+    description = "Object file displaying tool";
+    homepage    = https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man1/otool.1.html;
+    maintainers = with maintainers; [ lovek323 ];
+    platforms   = platforms.darwin;
+
+    longDescription = ''
+      The otool command displays specified parts of object files or libraries.
+      If the, -m option is not used, the file arguments may be of the form
+      libx.a(foo.o), to request information about only that object file and not
+      the entire library.
+    '';
+  };
+}
+