[llvm] [Offload] Store device info tree in device handle (PR #145913)

[Joseph Huber via llvm-commits]

================
@@ -167,31 +167,39 @@ void initPlugins() {
     for (auto DevNum = 0; DevNum < Platform.Plugin->number_of_devices();
          DevNum++) {
       if (Platform.Plugin->init_device(DevNum) == OFFLOAD_SUCCESS) {
-        Platform.Devices.emplace_back(ol_device_impl_t{
-            DevNum, &Platform.Plugin->getDevice(DevNum), &Platform});
+        auto Device = &Platform.Plugin->getDevice(DevNum);
+        auto Info = Device->obtainInfoImpl();
+        if (auto Err = Info.takeError())
+          return Err;
+        Platform.Devices.emplace_back(DevNum, Device, &Platform,
+                                      std::move(*Info));
       }
     }
   }
 
   // Add the special host device
   auto &HostPlatform = Context->Platforms.emplace_back(
-      ol_platform_impl_t{nullptr,
-                         {ol_device_impl_t{-1, nullptr, nullptr}},
-                         OL_PLATFORM_BACKEND_HOST});
+      ol_platform_impl_t{nullptr, OL_PLATFORM_BACKEND_HOST});
+  HostPlatform.Devices.emplace_back(-1, nullptr, nullptr, InfoTreeNode{});
   Context->HostDevice()->Platform = &HostPlatform;
 
   Context->TracingEnabled = std::getenv("OFFLOAD_TRACE");
   Context->ValidationEnabled = !std::getenv("OFFLOAD_DISABLE_VALIDATION");
 
   OffloadContextVal = Context;
+
+  return Plugin::success();
 }
 
 // TODO: We can properly reference count here and manage the resources in a more
 // clever way
 Error olInit_impl() {
   static std::once_flag InitFlag;
-  std::call_once(InitFlag, initPlugins);
+  std::optional<Error> InitResult{};
+  std::call_once(InitFlag, [&] { InitResult = initPlugins(); });
 
+  if (InitResult)
+    return std::move(*InitResult);
----------------
jhuber6 wrote:

Didn't we have a patch for this? We want the following to work as expected.
```
init()
deinit()
init()
deinit()
```

https://github.com/llvm/llvm-project/pull/145913