[Bug libstdc++/64797] 22_locale/conversions/string/2.cc FAILs

[howarth at bromo dot med.uc.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64797

--- Comment #3 from howarth at bromo dot med.uc.edu ---
Still present at r220189 on x86_64-apple-darwin14.