[llvm] [Offload] Make olLaunchKernel test thread safe (PR #149497)

[Joseph Huber via llvm-commits]

================
@@ -2227,6 +2227,7 @@ struct AMDGPUDeviceTy : public GenericDeviceTy, AMDGenericDeviceTy {
   /// Get the stream of the asynchronous info structure or get a new one.
   Error getStream(AsyncInfoWrapperTy &AsyncInfoWrapper,
                   AMDGPUStreamTy *&Stream) {
+    std::lock_guard<std::mutex> StreamLock{StreamMutex};
----------------
jhuber6 wrote:

Do we only need this when we create a new one?

https://github.com/llvm/llvm-project/pull/149497