* gtk/abicheck.sh: No need for INCLUDE_INTERNAL_SYMBOLS anymore.
* gdk/gdk.symbols: Don't use #if defined().
* gdk/Makefile.am (gdkalias.h):
* gtk/Makefile.am (gtkalias.h): Don't use cpp to filter gtk.symbols.
* gdk/makegdkalias.pl:
* gtk/makegtkalias.pl: Move the #ifdef processing into the perl script, and
keep the #ifdefs which differentiate between platforms.
* gtk/Makefile.am (gtk_private_h_sources): Remove gtkinternals.h, it is no
longer needed.