Sorry folks, I broke the build big time - and this time it was kinda on purpose.
In order to systematically track down all changes needed to fix PR 49074 (but for all architectures, and future proof), I added a link time test exercising the C++ 2011 <atomic> operations. The list of architectures this did NOT break on first try was: amd64, ppc64 and sparc64 (guess which two I tried upfront?). This should now be slightly better (i386 should pass as well, probably quite a few others), but it will take a few days to track down and squash the stranglers. Martin