[PATCH 01/10] posix-timers: Remove dead thread posix cpu timers caching

When a task is exiting or has exited, its posix cpu timers don't tick anymore and won't elapse further. It's too late for them to expire. So any further call to timer_gettime() on these timers will return the same remaining expiry time. The current code optimize this by caching the remaining delt

[RFC PATCH 01/10] posix-timers: Remove dead thread posix cpu timers caching

When a task is exiting or has exited, its posix cpu timers don't tick anymore and won't elapse further. It's too late for them to expire. So any further call to timer_gettime() on these timers will return the same remaining expiry time. The current code optimize this by caching the remaining delt