Update freetype to 2.5.4.

core/src/fpdfapi/fpdf_font/fpdf_font_charset.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
  
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "../../../include/fpdfapi/fpdf_page.h"
 #include "../../../include/fxge/fx_freetype.h"
 extern FX_WCHAR PDF_UnicodeFromAdobeName(const FX_CHAR*);
 const struct _UnicodeAlt {
@@ skipping 592 matching lines @@
     return NULL;
 }
 FX_DWORD PDF_PredefinedCharCodeFromUnicode(int encoding, FX_WCHAR unicode)
 {
     return PDF_FindCode(PDF_UnicodesForPredefinedCharSet(encoding), unicode);
 }
 #ifdef __cplusplus
 extern "C" {
 #endif
 extern int FXFT_unicode_from_adobe_name(const char* name);
+extern void FXFT_adobe_name_from_unicode(char* glyph_name, FX_WCHAR unicode);
 #ifdef __cplusplus
 }
 #endif
 FX_WCHAR PDF_UnicodeFromAdobeName(const FX_CHAR* name)
 {
     return (FX_WCHAR)(FXFT_unicode_from_adobe_name(name) & 0x7FFFFFFF);
 }
 CFX_ByteString PDF_AdobeNameFromUnicode(FX_WCHAR unicode)
 {
     char glyph_name[64];
     FXFT_adobe_name_from_unicode(glyph_name, unicode);
     return CFX_ByteString(glyph_name, -1);
 }