[XeTeX] XeTeX/xdvipdfmx: PDF text copying with double encoded fonts

[Akira Kakuto]

Hi Jiang,

> So there might still be value to fix the ToUnicode map, don't you think?
>
> I have an experimental patch at
> https://github.com/jjgod/texlive/commit/f01557d549aaf27584f624fa540f6b4b05349bf3
> in case you would like to build a w32tex binary for him to test.

I confirmed that after applying your patch, ToUnicode map becomes
correct, and copy&paste is fine for the example with
\XeTeXgenerateactualtext=0.
Interested users can replace binary for 32bit windows bin/win32/dvipdfmx.dll
by downloading:

http://www.w32tex.org/toolsw32/dvipdfmx.dll

Please commit your patch after Karl starts 2018/dev.

Best,
Akira