bug#41200: Displaying a tooltip with x-show-tip gets very slow as more faces are defined

[martin rudalics]

> Indeed, you're completely right; thanks!  Replacing face_alist and
> Vface_new_frame_defaults with hash tables makes the worst example
> about 10 times faster, and with that change tooltips now take 30 to
> 50ms to display instead of 500-600ms in my real-life use case (my
> usual config).  I have attached a patch.

GCC throws the following error here:

  CC       frame.o
In file included from ../../src/lisp.h:954,
                 from ../../src/frame.c:29:
../../src/frame.c: In function ‘make_frame’:
./globals.h:6365:14: error: incompatible type for argument 6 of 
‘make_hash_table’
 #define Qnil builtin_lisp_symbol (0)
              ^~~~~~~~~~~~~~~~~~~~~~~
../../src/frame.c:952:57: note: in expansion of macro ‘Qnil’
                         DEFAULT_REHASH_THRESHOLD, Qnil, Qnil));
                                                         ^~~~
In file included from ../../src/conf_post.h:39,
                 from ./config.h:2270,
                 from ../../src/frame.c:20:
../../src/lisp.h:3661:43: note: expected ‘_Bool’ but argument is of type 
‘Lisp_Object’ {aka ‘struct Lisp_Object’}
                              Lisp_Object, bool);
                                           ^~~~
make[1]: *** [Makefile:402: frame.o] Fehler 1
make[1]: *** Es wird auf noch nicht beendete Prozesse gewartet....
make[1]: Verzeichnis „/home/martin/emacs-git/release/obj-gtk/src“ wird verlassen
make: *** [Makefile:424: src] Fehler 2

martin