[llvm] [Offload] Ensure all `llvm::Error`s are handled (PR #137339)

[Joseph Huber via llvm-commits]

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@@ -390,13 +389,17 @@ ol_impl_result_t olDestroyEvent_impl(ol_event_handle_t Event) {
 ol_event_handle_t makeEvent(ol_queue_handle_t Queue) {
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jhuber6 wrote:

Probably need this to return an error, but unrelated.

https://github.com/llvm/llvm-project/pull/137339