Try to fix autotools build

src/Makefile.am

@@ -193,6 +193,16 @@ harfbuzz-subset.cc: Makefile.sources
 	|| ($(RM) $(srcdir)/harfbuzz-subset.cc; false)
 BUILT_SOURCES += harfbuzz-subset.cc
 
+lib_LTLIBRARIES += libharfbuzz-cairo.la
+libharfbuzz_cairo_la_LINK = $(chosen_linker) $(libharfbuzz_cairo_la_LDFLAGS)
+libharfbuzz_cairo_la_SOURCES = $(HB_CAIRO_sources)
+libharfbuzz_cairo_la_CPPFLAGS = $(HBCFLAGS) $(CODE_COVERAGE_CFLAGS)
+libharfbuzz_cairo_la_LDFLAGS = $(base_link_flags) $(export_symbols_subset) $(CODE_COVERAGE_LDFLAGS)
+libharfbuzz_cairo_la_LIBADD = libharfbuzz.la
+pkginclude_HEADERS += $(HB_CAIRO_headers)
+pkgconfig_DATA += harfbuzz-cairo.pc
+EXTRA_DIST += harfbuzz-cairo.pc.in
+
 if HAVE_ICU
 if HAVE_ICU_BUILTIN
 HBCFLAGS += $(ICU_CFLAGS)

src/Makefile.sources

@@ -376,6 +376,9 @@ HB_SUBSET_headers = \
 	hb-subset-repacker.h \
 	$(NULL)
 
+HB_CAIRO_sources = hb-cairo.cc hb-cairo-utils.cc hb-cairo-utils.hh
+HB_CAIRO_headers = hb-cairo.h
+
 HB_GOBJECT_DIST_sources = hb-gobject-structs.cc
 HB_GOBJECT_DIST_headers = hb-gobject.h hb-gobject-structs.h
 HB_GOBJECT_ENUM_sources = hb-gobject-enums.cc

src/harfbuzz-cairo.pc.in

@@ -0,0 +1,12 @@
+prefix=%prefix%
+exec_prefix=%exec_prefix%
+libdir=%libdir%
+includedir=%includedir%
+
+Name: harfbuzz cairo integration
+Description: HarfBuzz cairo integration
+Version: %VERSION%
+
+Requires: harfbuzz = %VERSION%
+Libs: -L${libdir} -lharfbuzz-cairo
+Cflags: -I${includedir}/harfbuzz