[llvm] [Offload] Add check-offload-unit for liboffload unittests (PR #137312)

[Joseph Huber via llvm-commits]

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@@ -65,6 +65,13 @@ ol_device_handle_t TestEnvironment::getDevice() {
   static ol_device_handle_t Device = nullptr;
 
   if (!Device) {
+    if (const char *EnvStr = getenv("OFFLOAD_UNITTEST_PLATFORM")) {
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jhuber6 wrote:

Lol, forgot about the host plugin and I doubt anyone cares about it. Honestly, the `liboffload` API probably shouldn't even present it to the user until someone cares enough to update it.

https://github.com/llvm/llvm-project/pull/137312