[Bug libstdc++/51906] thread lock test failures on darwin11 under Xcode 4.2

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51906

--- Comment #42 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-02-03 09:18:36 UTC ---
That header isn't even installed, let alone included, on other targets

Jack, if you test it please change == to >= in
libstdc++-v3/config/os/bsd/darwin/os_defines.h