* src/autofit/ft-hb.c: Decorate with `FT_LOCAL_DEF`.
Add ANSI boilerplate code for otherwise empty file.
* src/autofit/ft-hb.h: Include `compiler-macros.h` and `freetype.h`.
Use `FT_BEGIN_HEADER` and `FT_END_HEADER`.
Decorate with `FT_LOCAL`.
* src/autofit/rules.mk (AUTOF_DRV_SRC): Add `ft-hb.c`.
This is mandated by the C99 standard, and clang 15 produces zillions of
warnings otherwise.
* devel/ftoption.h, include/freetype/config/ftoption.h,
include/freetype/internal/ftmemory.h, src/autofit/afhints.h,
src/autofit/afmodule.c, src/autofit/aftypes.h, src/base/ftadvanc.c,
src/base/ftdbgmem.c, src/base/ftstream.c, src/bdf/bdflib.c,
src/truetype/ttinterp.c: Replace identifiers of the form `_foo` with `foo_`.
The circular dependency is still there, but at least we no longer depend on
the HarfBuzz API that is only present if HarfBuzz has been built with
FreeType support, making the bootstrapping a bit easier.
* src/autofit/ft-hb.c, src/autofit/ft-hb.h: New files, providing
`_hb_ft_font_create`, which is more or less a verbatim copy of the
corresponding HarfBuzz code from file `hb-ft.cc`.
* src/autofit/afglobal.c (af_face_globals_new): Use it.
* src/autofit/afshaper.h: Don't include `hb-ft.h` but `ft-hb.h`.
* src/autofit/autofit.c: Include `ft-hb.c`.
* LICENSE.TXT: Updated.
Werner Lemberg