[llvm] [libsycl] Add sycl::queue stub (PR #184110)

[Sergey Semenov via llvm-commits]

================
@@ -0,0 +1,33 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file contains the declaration of the SYCL async_handler type, which
+/// is a callable such as a function class or lambda, with an exception_list as
----------------
sergey-semenov wrote:

```suggestion
/// is a callable, such as a function class or lambda, with an exception_list as
```

https://github.com/llvm/llvm-project/pull/184110