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

[Akira Kakuto]

% luatex-plain test.tex
% luatex-plain is in the ConTeXt
\font\1="SourceHanSansSC-Regular.otf"
\font\2="SourceHanSerifSC-Regular.otf"
\font\3="msyh.ttf"

{\1 孤立子 ABC} \par
{\2 孤立子 ABC} \par
{\3 孤立子 ABC} \par

\bye

In the case of "luatex-plain" in the ConTeXt package,
copy&paste was OK by Adobe Reader DC for all
fonts (1), (2), and (3).

Best,
Akira