https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88879
--- Comment #15 from Alexander Monakov <amonakov at gcc dot gnu.org> --- This should not be reproducible with current HEAD because the assert was simply eliminated. If GCC master definitely fails, can you please provide the exact diagnostic? As for 9.2 this is sadly expected because the patch was not backported, I will backport it soon for the next release from the gcc-9 branch (but if you're building GCC yourself you can easily do it on your end as the patch simply removes the offending assert). Sorry about the trouble.
