The test previously assumed a default nice value of 0, but this can vary
depending on PAM configuration, /etc/security/limits.conf, or other environment
settings.
Fixes: https://github.com/libuv/libuv/issues/4898
Signed-off-by: Juan José Arboleda <soyjuanarbol@gmail.com>
Add uv_thread_setpriority for setting priority for threads created by
uv_thread_create. Add uv_thread_getpriority for getting thread priority.
For Linux by default, if the scheduling policy is SCHED_OTHER and the
priority is 0, we need to set the nice value.
Fixes: https://github.com/libuv/libuv/issues/4051