[Bug c++/71207] [5/6/7 Regression] gcc 5.3 and 6.1 generates wrong code with -O2

[vladimir.simonov at acronis dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71207

--- Comment #3 from Vladimir Simonov <vladimir.simonov at acronis dot com> ---
(In reply to Jakub Jelinek from comment #2)
> Started with r229859, -fno-devirtualize -O2 works.

Thank you for hint with workaround