[clang] [llvm] [Offload][Lang] Add blocking to LaunchKernel and Memcpy (PR #218049)

[Kevin Sala Penades via cfe-commits]

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@@ -22,9 +26,24 @@ enum class QueueKind {
 };
 
 struct StreamTy {
+  StreamTy(ol_queue_handle_t Queue, ol_device_handle_t Device, QueueKind Kind)
+      : Queue(Queue), Device(Device), Kind(Kind) {}
+
+  ol_result_t
+  waitOnAndTrackDependencyEvents(ArrayRef<ol_event_handle_t> Events);
+  ol_result_t syncStream();
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kevinsala wrote:

nit

```suggestion
  ol_result_t sync();
```

https://github.com/llvm/llvm-project/pull/218049