[OpenMP][Docs] Update clang support based on community discussion

[jdoerfert]

Summary

In the last meeting nobody could tell what was problematic for some of
the points so we mark them as done until we realize otherwise.

[ABataev]

LG

clang/docs/OpenMPSupport.rst

 | device extension             | clause: extended device                                      | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device extension             | clause: uses_allocators clause                               | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device extension             | clause: in_reduction                                         | :part:`worked on`        | r308768                                                               |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device extension             | omp_get_device_num()                                         | :part:`worked on`        | D54342                                                                |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device extension             | structure mapping of references                              | :none:`unclaimed`        |                                                                       |
+| device extension             | structure mapping of references                              | :part:`worked on`        |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device extension             | nested target declare                                        | :good:`done`             | D51378                                                                |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device extension             | implicitly map 'this' (this[:1])                             | :good:`done`             | D55982                                                                |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device extension             | allow access to the reference count (omp_target_is_present)  | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device extension             | requires directive                                           | :part:`partial`          |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device extension             | clause: unified_shared_memory                                | :good:`done`             | D52625,D52359                                                         |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device extension             | clause: unified_address                                      | :part:`partial`          |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device extension             | clause: reverse_offload                                      | :none:`unclaimed parts`  | D52780                                                                |
+| device extension             | clause: reverse_offload                                      | :part:`unclaimed parts`  | D52780                                                                |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device extension             | clause: atomic_default_mem_order                             | :good:`done`             | D53513                                                                |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device extension             | clause: dynamic_allocators                                   | :part:`unclaimed parts`  | D53079                                                                |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device extension             | user-defined mappers                                         | :part:`worked on`        | D56326,D58638,D58523,D58074,D60972,D59474                             |
+| device extension             | user-defined mappers                                         | :good:`done`             | D56326,D58638,D58523,D58074,D60972,D59474                             |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device extension             | mapping lambda expression                                    | :good:`done`             | D51107                                                                |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device extension             | clause: use_device_addr for target data                      | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device extension             | support close modifier on map clause                         | :good:`done`             | D55719,D55892                                                         |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device extension             | teams construct on the host device                           | :part:`done`             | r371553                                                               |
+| device extension             | teams construct on the host device                           | :good:`done`             | r371553                                                               |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | device extension             | support non-contiguous array sections for target update      | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device extension             | pointer attachment                                           | :none:`unclaimed`        |                                                                       |
+| device extension             | pointer attachment                                           | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| device extension             | map clause reordering based on map types                     | :none:`unclaimed`        |                                                                       |
+| device extension             | map clause reordering based on map types                     | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | atomic extension             | hints for the atomic construct                               | :good:`done`             | D51233                                                                |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | base language                | C11 support                                                  | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | base language                | C++11/14/17 support                                          | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | base language                | lambda support                                               | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | misc extension               | array shaping                                                | :good:`done`             | D74144                                                                |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| misc extension               | library shutdown (omp_pause_resource[_all])                  | :none:`unclaimed parts`  | D55078                                                                |
+| misc extension               | library shutdown (omp_pause_resource[_all])                  | :part:`unclaimed parts`  | D55078                                                                |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | misc extension               | metadirectives                                               | :part:`worked on`        |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | misc extension               | conditional modifier for lastprivate clause                  | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | misc extension               | iterator and multidependences                                | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | misc extension               | depobj directive and depobj dependency kind                  | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| misc extension               | user-defined function variants                               | :part:`worked on`        | D67294, D64095, D71847, D71830                                        |
+| misc extension               | user-defined function variants                               | :good:`done`             | D67294, D64095, D71847, D71830                                        |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | misc extension               | pointer/reference to pointer based array reductions          | :none:`unclaimed`        |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | misc extension               | prevent new type definitions in clauses                      | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | memory model extension       | memory model update (seq_cst, acq_rel, release, acquire,...) | :good:`done`             |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+