This option was added in bug 337887 as a woraround for GCC/binutils limitations. It's not needed in recent versions and I don't think we care about such an old setup anymore. It causes problems like one already worked around in bug 451024, where thunks are needed for cross-dll calls, which may be unloaded too early. I recently got a report about such problem from TOR Project: https://trac.torproject.org/projects/tor/ticket/10761

This change was originally made in this commit: https://hg.mozilla.org/projects/nss/rev/099480454292 I don't know if this change is reasonable. If you're working with MinGW and say this is required, I'll have to trust you. Given this isn't affecting our default Windows builds (which I believe use MS compilers), I'll give you r+. I wish there was a second person doing MinGW builds and who could ack your change.