[dvipdfmx] Incorrect faked bold font in xetex

[Hironobu Yamashita]

Hi,

I found a issue report https://github.com/pgf-tikz/pgf/issues/692
and I think this is a dvipdfmx issue. MWE:

\font\x=cmss10\x
\font\zzz="[XITS-Regular.otf]:embolden=5" at 10pt
{\zzz a}
\hbox{%
  \special{pdf:btrans matrix 1 0 0 1 0 0}%
  A%
  \special{pdf:etrans}%
  B%
}
\bye

The font of "B" is cmss10 but it is emboldened.
Other native font features (slant, extend, color) are fine.

Best,
Hironobu