bug#51252: [core-updates-frozen] lualatex needs additional setup

[Ricardo Wurmus]

“texlive-latex-base” provides that file.  We disable a whole bunch 
of formats that we cannot build that early in the process, and 
then we run fmtutil-sys on the patched file.
The cause for trouble lies in texlive-kpathsea, which provides 
share/texmf-dist/web2c/fmtutil.cnf 
.  That file states how to build the various fmt files.

The file in the earlier version of Tex Live contains this line for the lualatex 
format:

   lualatex luatex language.dat,language.dat.lua lualatex.ini

the new file (on core-updates-frozen) says this:

   lualatex luahbtex language.dat,language.dat.lua lualatex.ini

i.e. it will try to build the lualatex fmt file with luahbtex 
instead of luatex.  I suppose at this point in the build we don’t 
actually have a working luahbtex, so fmtutil-sys doesn’t generate 
the correct lualatex.fmt.

I’m not sure how to fix this, but I guess we can avoid a world 
rebuild by adding an extra package that installs a working 
lualatex.fmt file.

--
Ricardo