[Bug libstdc++/54025] atomic won't compile: chrono::duration::duration() is not C++11 compliant

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54025

--- Comment #9 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-07-19 
12:19:05 UTC ---
Another option would be to give duration::__rep a NSDMI, which leaves the
testcase valid (as a QoI feature, I believe)