Add HarfBuzz fallbacks for libotf functions used in ftfont_list

* src/ftfont.c [!HAVE_LIBOTF && HAVE_HARFBUZZ]: Include hb-ot.h.
(OTF, OTF_tag) [!HAVE_LIBOTF && HAVE_HARFBUZZ]: New typedefs.
(hbotf_open, hbotf_check_features) [!HAVE_LIBOTF && HAVE_HARFBUZZ]: New
functions.
(OTF_open, OTF_close, OTF_check_features) [!HAVE_LIBOTF && HAVE_HARFBUZZ]:
New macros.
(ftfont_list) [!HAVE_LIBOTF && HAVE_HARFBUZZ]: Use them.
1 job for master in 60 minutes and 18 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
failed #2375
test-all

01:00:18

 
Name Stage Failure
failed
test-all Test
make[2]: *** [check-doit] Error 1
Makefile:318: recipe for target 'check-doit' failed
make[2]: Leaving directory '/builds/emacs/emacs/test'
make[1]: *** [check-expensive] Error 2
Makefile:293: recipe for target 'check-expensive' failed
make[1]: Leaving directory '/builds/emacs/emacs/test'
make: *** [check-expensive] Error 2
Makefile:959: recipe for target 'check-expensive' failed
ERROR: Job failed: exit code 1