[llvm] [SYCL] Add platform enumeration and info query using liboffload (PR #166927)

[Dmitry Rogozhkin via llvm-commits]

================
@@ -0,0 +1,38 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 helpers for info descriptors
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBSYCL___IMPL_INFO_DESC_BASE_HPP
+#define _LIBSYCL___IMPL_INFO_DESC_BASE_HPP
+
+#include <sycl/__impl/detail/config.hpp>
+
+_LIBSYCL_BEGIN_NAMESPACE_SYCL
+
+namespace detail {
+
+template <typename Desc, typename DescOf> struct info_desc_tag {};
+template <typename Desc, typename DescOf, typename = void>
+struct is_info_desc : std::false_type {};
+template <typename Desc, typename DescOf>
+struct is_info_desc<
----------------
dvrogozh wrote:

Is that of any style requirement to tight pack declarations? Imho, it would be nice to have visually separate blocks, something like:
```suggestion
template <typename Desc, typename DescOf> struct info_desc_tag {};

template <typename Desc, typename DescOf, typename = void>
struct is_info_desc : std::false_type {};

template <typename Desc, typename DescOf>
struct is_info_desc<
```

https://github.com/llvm/llvm-project/pull/166927