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

[Joseph Huber via llvm-commits]

================
@@ -104,3 +104,15 @@ def : Function {
     Return<"OL_ERRC_INVALID_DEVICE">
   ];
 }
+
+def : Function {
+  let name = "olGetHostDevice";
----------------
jhuber6 wrote:

Hm, it's possible we should have both. Since I feel like the average user will just want to "do this for every device" as the normal path.

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