Fix for emscripten builds.

modules/freetype/freetype-2.6.3/src/autofit/aftypes.h

@@ -221,7 +221,8 @@ extern void*  _af_debug_hints;
   (*AF_WritingSystem_InitHintsFunc)( AF_GlyphHints    hints,
                                      AF_StyleMetrics  metrics );
 
-  typedef void
+//  typedef void
+  typedef int
   (*AF_WritingSystem_ApplyHintsFunc)( FT_UInt          glyph_index,
                                       AF_GlyphHints    hints,
                                       FT_Outline*      outline,