* revert `rb_last_status_set`
* renamed the new function as `rb_process_status_new`
* `rb_process_status_new` always freezes the return value
* marked `Process::Status.wait` as EXPERIMENTAL, as it has not
been discussed totally yet.
getaddrinfo_a() gets stuck after fork().
To avoid this, we need 1 second sleep to wait for internal
worker threads of getaddrinfo_a() to be finished, but that is unacceptable.
[Bug #17220] [Feature #17134] [Feature #17187]
Previously, rb_getaddrinfo_a_before_exec() is called from before_exec().
However, the function needs to be called only before fork().
The change moves it to before_fork().
We need stop worker threads in getaddrinfo_a() before fork().
This change adds a hook before fork() that cancel all outstanding requests
and wait for all ongoing requests. Then, it waits for all worker
threads to be finished.
Fixes [Bug #17220]
