[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 #29 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-01-31 
01:18:37 UTC ---
It might be easier if I to get access to a darwin system, which I should have
in a few days so I can test it myself.