adds Freetype patches to address build issue on OS X

tools/scripts/install/ttfautohint-build.sh

@@ -23,7 +23,10 @@ TTFAUTOHINT_VERSION="1.6"
 
 # Necessary patches (lists of at most 10 URLs each separated by whitespace,
 # to be applied in order).
-FREETYPE_PATCHES=""
+FREETYPE_PATCHES="\
+  http://git.savannah.gnu.org/cgit/freetype/freetype2.git/patch/?id=c9a9cf59 \
+  http://git.savannah.gnu.org/cgit/freetype/freetype2.git/patch/?id=c8829e4b \
+"
 HARFBUZZ_PATCHES=""
 TTFAUTOHINT_PATCHES=""