Add U+2212 to Japanese converters and update GBK/gb18030 aliases/tables

README.chromium

 Name: icu
 URL: http://site.icu-project.org/
 Version: 54.1
 License: MIT
 Security Critical: yes
 
 Description:
 This directory contains the source code of ICU 54.1 for C/C++.
 
 
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     and aliases required by the WHATWG Encoding spec plus a few extra (see
     the file as to why).
 
   - Add source/data/mappings/ucmlocal.txt : to list only converters we need.
 
   - Add new tables per the WHATWG encoding standards for EUC-JP,
     Shift_JIS, Big5 (Big5+Big5HKSCS), EUC-KR and all the single byte encodings.
     They're generated with scripts :
       scripts/{eucjp,sjis,big5,single_byte}_gen.sh
 
+  - gb_table.patch
+    1. Map \xA3\xA0 to U+3000 instead of U+E5E5 in gb18030 and windows-936 per
+    the encoding spec (one-way mapping in toUnicode direction).
+    2. Map \xA8\xBF to U+01F9 instead of U+E7C8. Add one-way map
+    from U+1E3F to \xA8\xBC (windows-936/GBK).
+       See https://www.w3.org/Bugs/Public/show_bug.cgi?id=28740#c3
+
   - uconv.patch
     a. ISO-2022-JP-[1-4] is dropped.
     b. SCSU, BOCU, ISCII, UTF-7, LMB, ibm42*, ISO-2022-{KR,CN*} and HZ-GB  :
        converters and detectors are dropped leading to the ~100kB reduction
        in the code size.
 
   - Upstream bugs
     http://www.icu-project.org/trac/ticket/11296 (uconv.patch)
     http://www.icu-project.org/trac/ticket/10303 (html5 encoding tables)
 
@@ skipping 186 matching lines @@
      http://bugs.icu-project.org/trac/ticket/11358
      http://bugs.icu-project.org/trac/ticket/11623
 
 16. Properly handle a converter name starting with 'x-'.
    - patches/ucnv_name.patch
    - upstream bug
      http://bugs.icu-project.org/trac/ticket/11696