http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50337
--- Comment #2 from Colin Watson <cjwatson at ubuntu dot com> 2011-09-08 17:09:45 UTC --- http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=625756 reports that this happens at least as far back as GCC 4.5, and https://buildd.debian.org/status/fetch.php?pkg=electric-fence&arch=amd64&ver=2.1.16&stamp=1273852143 suggests that this worked in GCC 4.4.3.
