[offload] add tests for event synchronization (#193927)
This patch adds:
- a new kernel `void single_counter(int32_t init_loop, int32_t addend,
uint32_t *init_val, uint32_t *out)`
- a new test suite `olLaunchKernelSingleCounterSyncEventTest`, with two
tests
The test `SuccessSyncEvent` verifies whether `olSyncEvent(Event)` awaits
the completion of `Event`.
The test `SuccessTwoQueues` checks the correctness of the
synchronization between queues using events. Enqueueing the kernel on
the queue `Q1` should produce `Result1`, which is used as an initial
value for the queue `Q2`. Therefore, before executing any future work,
`Q2` should wait for the event `Event1`, which is created after
submitting work on `Q1`. The required synchronization is ensured by
`olWaitEvents(Q2, &Event1, 1)`. If `Q2` uses the value passed as
`Result1` before the work on `Q1` has completed, the result of the
kernel enqueued on `Q2` would be incorrect.
