[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:

That makes sense, I agree it would be good to keep it as flexible as possible. I'm maybe missing something but what would that look like for copies to or from host memory? One possibility is the device handles could be optionally null to imply host addresses but I'm not sure if that's cleaner than having separate entry points for host-to-device and device-to-host copies.

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