Use a cache on Haiku to avoid constantly reading fonts during font lookup

Use a cache on Haiku to avoid constantly reading fonts during font lookup

* src/haiku_font_support.cc (struct font_object_cache_bucket):
New struct.
(language_code_points): Make `int'.
(hash_string): New function.
(cache_font_object_data, lookup_font_object_data)
(font_object_has_chars): New functions.
(font_check_wanted_chars, font_check_one_of)
(font_check_language): Lookup in cached font object instead.
(be_init_font_data, be_evict_font_cache): New functions.

* src/haiku_support.h (struct haiku_font_pattern): Make
`uint32_t's ints instead.
* src/haikufont.c (haikufont_apply_registry, syms_of_haikufont):
Adjust for those changes.

* src/haikuterm.c (haiku_frame_up_to_date): Clear font lookup
cache every 50 updates.