[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 #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-01-19 
19:58:04 UTC ---
have they been failing since I enabled them by fixing PR 50196 ?