[llvm] [Offload] Implement the remaining initial Offload API (PR #122106)

[Callum Fare via llvm-commits]

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@@ -16,8 +16,8 @@ def : Function {
     let details = [];
     let params = [
         Param<"ol_queue_handle_t", "Queue", "handle of the queue", PARAM_IN>,
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callumfare wrote:

Sorry I didn't actually see your last comment, I think everything I said above applies though. 

One other issue I can see is who owns host allocations. If you make an allocation on the host plugin, that's not the same as a host allocation made by one of the other plugins (since memory is managed, pinned, etc).

https://github.com/llvm/llvm-project/pull/122106