+ The idle task decides to enter sleep mode on the following line.
```
if( xExpectedIdleTime >= configEXPECTED_IDLE_TIME_BEFORE_SLEEP )
```
+ The scheduler is suspended, preventing any context switches.
[Potentially a tick interrupt could occur here. That could happen if other tasks executing consumed a lot of time since the above code line executed. If a tick interrupt occurs here the interrupt will be entered but the interrupt will not do anything other than increment xPendedTicks.]
+ The expected idle time is checked again. No context switches can occur now so the code will execute until the scheduler is unsuspended. Assuming configEXPECTED_IDLE_TIME_BEFORE_SLEEP is set to a sensible value, a tick interrupt won't occur for some time.
+ portSUPPRESS_TICKS_AND_SLEEP() is called.
+ The default implementation of the tickless function calls eTaskConfirmSleep() - which prior to this change does not return eAbortSleep even though xPendedTicks is not 0, and after this change does return eAbortSleep.
