[llvm] [Offload] Improve `olDestroyQueue` logic (PR #153041)

[Ross Brunton via llvm-commits]

RossBrunton wrote:

This allows code to quickly create "microqueues" and not worry about tracking when they resolve.

For example:

```c++
ol_queue_handle_t Queue;
olQueueCreate(&Queue);
... Do something with the queue.
olQueueRelease(Queue);
```

https://github.com/llvm/llvm-project/pull/153041