The example below crashes LuaTeX with a segmentation fault. It is reproducible
with LuaTeX 1.10.1 7143 and LuaTeX 1.11.2 7226. To this end I built 7226 from
source with --debugopt to get a backtrace, which can be found below as well.
confirmed, we will see asap
(btw, I use --debug ie CFLAGS="-g -O0" because it's hard to follow the flow of optimized code)