OFX binaries run their own global init on the first
OfxGetNumberOfPlugins query, and that init is not thread-safe: two
threads racing to load the CImg fixture corrupted its static map
(SIGSEGV/SIGABRT, and a hang when the loader deadlocked). Tests create
their own PluginCache instances, so per-cache locks cannot serialize it;
add a process-wide LOAD_LOCK around dlopen + collect_plugins. Loading is
a startup-time operation, so the lock is free in production and makes
concurrent scans safe.
Mike-Solar
deb55d770e