Gtk-2.24.0 tarball doesn't build on quartz

[John Ralls <jralls ceridwen us>]

Undefined symbols:
  "_gtk_combo_box_text_new", referenced from:
      _create_combo_box in sizegroup.o
      _attach_widgets in textview.o
  "_gtk_combo_box_text_new_with_entry", referenced from:
      _do_combobox in combobox.o
  "_gtk_combo_box_text_append_text", referenced from:
      _do_combobox in combobox.o
      _do_combobox in combobox.o
      _do_combobox in combobox.o
      _do_combobox in combobox.o
      _create_combo_box in sizegroup.o
      _attach_widgets in textview.o
      _attach_widgets in textview.o
      _attach_widgets in textview.o

Something went wrong during autogen so that gtk/gtkcomboboxtext.lo isn't included with its gtkcombobox friends in am__objects_17. Building quartz from git works fine, and has done for several weeks. 

Since autogen.sh isn't included in the tarball this isn't easily repairable by users.

Regards,
John Ralls