[Bug middle-end/57974] std::pow(std::complex<long double>(0),1) returns (-nan,-nan)

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57974

--- Comment #9 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Or maybe should be made a little weaker / safer? Are you 100% sure we are
beating performancewise clang and icc on this?