[Bug tree-optimization/67816] [6 Regression] ICE in duplicate_thread_path, 186.crafty fails to build

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67816

--- Comment #10 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
Started with r228306.