[Bug libstdc++/60637] --fast-math breaks std::signbit function

[daniel.kruegler at googlemail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60637

--- Comment #1 from Daniel Krügler <daniel.kruegler at googlemail dot com> ---
This seems to be fixed in 4.9.0 trunk. My guess is that this was solved via bug
58625.