The fallback (Switch, BSDs, anything not Windows/Linux/Android/Apple) mixed
clocks: time_now_d() read the wall clock with gettimeofday, time_now_raw()
and Instant a monotonic one, from_time_raw() didn't subtract the start time,
and time_to_unix_utc() added the timestamp to the current time instead of
the start time.
Now every non-Windows platform shares the same code, built on time_now_raw()
and time_now_unix_utc(). Those two use clock_gettime where we know it's there
and std::chrono's steady_clock/system_clock elsewhere. Instant stores a
single nanosecond timestamp, and time_to_unix_utc() (which was missing on
Linux/Android/Apple) is start time plus timestamp, like on Windows.
The time origin is now set in TimeInit() rather than lazily on the first
time_now_d(), which raced between threads. iOS never called TimeInit(), so
it does now.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
sleep_ms() should generally be avoided when possible. This can be used to try
to track down unnecessary sleeps by adding some logging.
This commit on its own doesn't actually add any logging.
* Add yield() function to tell the CPU that we're busy-waiting (rare)
Use it only for the busy-wait in lag sync, which only happens in
Windows.
* Buildfix attempt
