Roll HarfBuzz to 1.2.6

third_party/harfbuzz-ng/src/hb-ot-shape-complex-thai.cc

 /*
  * Copyright © 2010,2012  Google, Inc.
  *
  *  This is part of HarfBuzz, a text shaping library.
  *
  * Permission is hereby granted, without written agreement and without
  * license or royalty fees, to use, copy, modify, and distribute this
  * software and its documentation for any purpose, provided that the
  * above copyright notice and the following two paragraphs appear in
  * all copies of this software.
@@ skipping 121 matching lines @@
     {0x0E4Du, 0xF711u, 0xF899u}, /* NIKHAHIT */
     {0x0000u, 0x0000u, 0x0000u}
   };
   static const thai_pua_mapping_t RD_mappings[] = {
     {0x0E0Du, 0xF70Fu, 0xF89Au}, /* YO YING */
     {0x0E10u, 0xF700u, 0xF89Eu}, /* THO THAN */
     {0x0000u, 0x0000u, 0x0000u}
   };
 
   switch (action) {
-    default: assert (false); HB_FALLTHROUGH;
     case NOP: return u;
     case SD:  pua_mappings = SD_mappings; break;
     case SDL: pua_mappings = SDL_mappings; break;
     case SL:  pua_mappings = SL_mappings; break;
     case RD:  pua_mappings = RD_mappings; break;
   }
   for (; pua_mappings->u; pua_mappings++)
     if (pua_mappings->u == u)
     {
       hb_codepoint_t glyph;
@@ skipping 220 matching lines @@
   NULL, /* data_destroy */
   preprocess_text_thai,
   NULL, /* postprocess_glyphs */
   HB_OT_SHAPE_NORMALIZATION_MODE_DEFAULT,
   NULL, /* decompose */
   NULL, /* compose */
   NULL, /* setup_masks */
   HB_OT_SHAPE_ZERO_WIDTH_MARKS_BY_GDEF_LATE,
   false,/* fallback_position */
 };