https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83660
--- Comment #6 from kelvin at gcc dot gnu.org --- For what it's worth, I reconfigured my build with --enable-checking=yes,tree in hopes that this would help us find the C++ parser code that is responsible for creating the problematic syntax tree. The resulting compiler produces the exact same ICE with the same backtrace as has been captured already in these comments.