Libuv loaded and unloaded the Core Services and Application Services for
every call to uv_set_process_title().
Change that to load them on the first call to uv_set_process_title() and
delay unloading until libuv is unloaded.
Speeds up process_title_threadsafe by about 10x on my system. It should
fail less often (hopefully not at all) on the CI now.
PR-URL: https://github.com/libuv/libuv/pull/2480
Reviewed-By: Saúl Ibarra Corretgé <s@saghul.net>