deps: backport 3eb6764a from libuv upstream

Original commit message:

    win: fix unsavory rwlock fallback implementation

    Before this patch an uv_mutex_t (backed by a critical section) could be
    released by a tread different from the thread that acquired it, which is
    not allowed. This is fixed by using a semaphore instead.

    Note that the affected code paths were used on Windows XP and Windows
    Server 2003 only.

    Fixes: https://github.com/libuv/libuv/issues/515
    PR-URL: https://github.com/libuv/libuv/pull/516


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>

PR-URL: https://github.com/nodejs/node-private/pull/54


Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>