Bug#930292: texlive-luatex: lualatex uses huge memory for Noto CJK fonts

[Ryutaroh Matsumoto <ryutaroh.matsumoto@nagoya-u.jp>]

> luahbtex should behave better, right, if the font is loaded with the
> harf renderer selected?

Ah, you seems right. But, when I added [RawFeature={mode=harf}] to
the example given at the beginning of this report and processed the file
with lualatex-dev in TeXLive 2019 of February 14, the memory comsumption
was again mere 2GB... (I did it on last Saturday).

{mode=harf} can possibly behave better as we do not observe the huge
memory comsumption in xelatex, but I have personally not digged into
that possiblitty as the lualatex-ja developer recommends not to use
{mode=harf} with lualatex-ja as

\paragraph{Using \LuaTeX-ja with LuaHB\TeX}
Using \LuaTeX-ja with LuaHB\TeX (\LuaTeX\ integrated with
\href{https://github.com/harfbuzz/harfbuzz}{HarfBuzz}) is not well tested.
Maybe documents can typeset without an error,
but with unwanted results (especially, vertical typesetting and \cs{CID}).
Especially,
\emph{We don't recommend defining a Japanese font with HarfBuzz},
by specifying \texttt{Renderer=Harfbuzz}~etc.\ (\Pkg{fontspec}) or~{mode=harf} (otherwise).

at https://ja.osdn.net/projects/luatex-ja/scm/git/luatexja/blobs/master/doc/luatexja.dtx

Best regards, Ryutaroh