/usr/share/vim/addons/ is in vim-syntax-gtk 20110314-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/vim/addons/syntax/
/usr/share/vim/addons/syntax/atk.vim
/usr/share/vim/addons/syntax/atspi.vim
/usr/share/vim/addons/syntax/cairo.vim
/usr/share/vim/addons/syntax/clutter.vim
/usr/share/vim/addons/syntax/dbusglib.vim
/usr/share/vim/addons/syntax/evince.vim
/usr/share/vim/addons/syntax/gail.vim
/usr/share/vim/addons/syntax/gconf.vim
/usr/share/vim/addons/syntax/gdk.vim
/usr/share/vim/addons/syntax/gdkpixbuf.vim
/usr/share/vim/addons/syntax/gimp.vim
/usr/share/vim/addons/syntax/gio.vim
/usr/share/vim/addons/syntax/glib.vim
/usr/share/vim/addons/syntax/gnomedesktop.vim
/usr/share/vim/addons/syntax/gnomevfs.vim
/usr/share/vim/addons/syntax/gobject.vim
/usr/share/vim/addons/syntax/gobjectintrospection.vim
/usr/share/vim/addons/syntax/goocanvas.vim
/usr/share/vim/addons/syntax/gstreamer.vim
/usr/share/vim/addons/syntax/gtk.vim
/usr/share/vim/addons/syntax/gtkglext.vim
/usr/share/vim/addons/syntax/gtksourceview.vim
/usr/share/vim/addons/syntax/jsonglib.vim
/usr/share/vim/addons/syntax/libglade.vim
/usr/share/vim/addons/syntax/libgnome.vim
/usr/share/vim/addons/syntax/libgnomecanvas.vim
/usr/share/vim/addons/syntax/libgnomeui.vim
/usr/share/vim/addons/syntax/libgsf.vim
/usr/share/vim/addons/syntax/libnotify.vim
/usr/share/vim/addons/syntax/liboil.vim
/usr/share/vim/addons/syntax/librsvg.vim
/usr/share/vim/addons/syntax/libsoup.vim
/usr/share/vim/addons/syntax/libunique.vim
/usr/share/vim/addons/syntax/libwnck.vim
/usr/share/vim/addons/syntax/orbit2.vim
/usr/share/vim/addons/syntax/pango.vim
/usr/share/vim/addons/syntax/poppler.vim
/usr/share/vim/addons/syntax/vte.vim
/usr/share/vim/addons/syntax/xlib.vim