[Bug libstdc++/52681] [C++11] Using std::thread without -pthread crashes without warning

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52681

--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-04-18 
14:16:20 UTC ---
Entirely feasible, and probably safe enough for the 4.6 and 4.7 branches too.