[clang] [OpenMP] Add docs for fb_nullify/fb_preserve (PR #169558)

[Abhinav Gaba via cfe-commits]

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@@ -633,7 +633,8 @@ implementation.
 |                                                             |                           |                           | RT: @abhinavgaba (https://github.com/llvm/llvm-project/pull/149036,      |
 |                                                             |                           |                           | https://github.com/llvm/llvm-project/pull/158370)                        |
 +-------------------------------------------------------------+---------------------------+---------------------------+--------------------------------------------------------------------------+
-
+| need_device_ptr modifier for adjust_args clause             | :part:`unclaimed`         | :none:`unclaimed`         | Clang Parsing/Sema: https://github.com/llvm/llvm-project/pull/168905     |
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abhinavgaba wrote:

``:part:`partial` `` is probably better for consistency.

https://github.com/llvm/llvm-project/pull/169558