[Bug libstdc++/60695] std::atomic<X> doesn't work when X is of zero size

[roman at binarylife dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60695

--- Comment #3 from Roman Kononov <roman at binarylife dot net> ---
Yes, it is definitely silly in some sense. But, some templated user code might
become more complex with this behaviour. If gcc supports zero-sized objects it
would be nice to support them fully. The implementation for this case might do
the synchronization part without any data exchange.