[Bug middle-end/67005] [5/6 Regression] ICE: in verify_loop_structure, at cfgloop.c:1647 (loop with header n not in loop tree)

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67005

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Yeah, though "somewhere" would be all the time if we and up removing an edge.
I've meant to see whether we can restrict it to "removed an edge with
IRREDUCIBLE_LOOP flag set, but then we'd have to compute that first and we
only do that for 'aggressive' aka CDDCE.

Didn't get around to play with that ;)  (note the ICE appears after CDDCE
only, but I would need to convince myself that regular DCE can't trigger
the same issue - I think it can't)