[Bug libstdc++/54172] [4.7/4.8 Regression] __cxa_guard_acquire thread-safety issue

[rth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54172

--- Comment #11 from Richard Henderson <rth at gcc dot gnu.org> 2012-09-06 
18:53:25 UTC ---
The combined patch set also looks ok.

Talking with bkoz, he would like to see more comments added,
since a reasonable testcase seems unlikely.