https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65771
--- Comment #5 from ktkachov at gcc dot gnu.org ---
The code around the gcc_unreachable is:
#ifdef ENABLE_CHECKING
/* Otherwise this is a generic code; we should just lists all of
these explicitly. We forgot one. */
gcc_unreachable ();
#else
/* In a release build, we want to degrade gracefully: better to
generate incomplete debugging information than to crash. */
return NULL;
#endif
This will be hit only with checking enabled and the alternative seems to be
incomplete debugging info.
