[Bug c++/50871] [C++0x] G++ fails to reject explicitly-defaulted function definition with different exception spec in system headers

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50871

--- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> 2011-10-26 13:37:23 UTC ---
Are the libstdc++ headers treated as system headers when building the library
itself?  If so, that seems like the thing to fix.