Move common HarfBuzz code to a common file hbfont.c
* src/hbfont.c: New file, with code moved from w32uniscribe.c and renamed/modified as appropriate. * src/w32uniscribe.c: Move to hbfont.c DEF_DLL_FN and macro definitions for HarfBuzz functions used in hbfont.c (load_harfbuzz_funcs): Move loading of HarfBuzz functions used by hbfont.c to hbfont.c:hbfont_init_w32_funcs, and call that function from here. (syms_of_w32uniscribe_for_pdumper): Fill the 'shape' and 'combining_capability' members with hbfont.c function names. * src/w32common.h (hbfont_init_w32_funcs) [HAVE_HARFBUZZ]: Add prototype. * src/font.h (hbfont_shape, hbfont_combining_capability) [HAVE_HARFBUZZ]: Add prototypes. * src/Makefile.in (SOME_MACHINE_OBJECTS): Add hbfont.o. * configure.ac (FONT_OBJ): Add hbfont.o if HAVE_HARFBUZZ.