http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59543
--- Comment #3 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- It turned out to be a problem with debugging information. Some files in libjs_static.a are build with "-g", even when Firefox is configured with --disable-debug --disable-debug-symbols. If I add -g to the g++ invocation above, or build the object files in libjs_static.a without -g, the issue goes away.
