[Bug sanitizer/61591] Undefined behavior sanitizer does not catch builtin_unreachable's from impossible devirtualization

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61591

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Recently I rewrote the implementation of -fsanitize=unreachable and now I get
an Illegal instruction on the testcase attached.  So is there anything else to
do?