external/harfbuzz: Remove hidden dependency on freetype

In external/harfbuzz/ExternalProject_harfbuzz.mk we are careful to configure
harfbuzz --with-freetype=no, but then harfbuzz goes on to nevertheless link some
of its programs against freetype.  However, those all appear to be test programs
that we do not otherwise rely on, so just suppress building them in the first
place.

(I ran into this when trying to do a 32-bit Linux build in a 64-bit environment,
with only very limited 32-bit support installed in the system.)

Change-Id: I1bab2ff4b533e5a30d68d72ec001904cb63f5d94
Reviewed-on: https://gerrit.libreoffice.org/28963Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
Tested-by: Stephan Bergmann <sbergman@redhat.com>

external/harfbuzz/UnpackedTarball_harfbuzz.mk

@@ -15,6 +15,7 @@ $(eval $(call gb_UnpackedTarball_set_patchlevel,harfbuzz,0))
 
 $(eval $(call gb_UnpackedTarball_add_patches,harfbuzz, \
     external/harfbuzz/ubsan.patch \
+    external/harfbuzz/no-freetype.patch \
 ))
 
 ifneq ($(ENABLE_RUNTIME_OPTIMIZATIONS),TRUE)

external/harfbuzz/no-freetype.patch

+--- src/Makefile.in
++++ src/Makefile.in
+@@ -149,9 +149,7 @@
+ @HAVE_GOBJECT_TRUE@	$(HB_GOBJECT_ENUM_headers) \
+ @HAVE_GOBJECT_TRUE@	$(NULL)
+ 
+-noinst_PROGRAMS = main$(EXEEXT) test$(EXEEXT) \
+-	test-buffer-serialize$(EXEEXT) test-size-params$(EXEEXT) \
+-	test-would-substitute$(EXEEXT) $(am__EXEEXT_1)
++noinst_PROGRAMS = main$(EXEEXT) $(am__EXEEXT_1)
+ bin_PROGRAMS =
+ check_PROGRAMS = test-ot-tag$(EXEEXT) $(am__EXEEXT_1)
+ TESTS = $(am__EXEEXT_2) $(check_PROGRAMS)