[OpenMP][Docs] Update OpenMP supported features table (#126292)

Updated status to 'done' for OpenMP 6.0 features:
  - OpenMP directives in concurrent loop regions
  - atomics constructs on concurrent loop regions
  - Lift nesting restriction on concurrent loop

Removed duplicate OpenMP 6.0 feature per Michael Klemm:
  - atomic constructs in loop region

Author: ddpagan

clang/docs/OpenMPSupport.rst

@@ -416,9 +416,9 @@ implementation.
 +-------------------------------------------------------------+---------------------------+---------------------------+--------------------------------------------------------------------------+
 | safe_sync and progress with identifier and API              | :none:`unclaimed`         | :none:`unclaimed`         |                                                                          |
 +-------------------------------------------------------------+---------------------------+---------------------------+--------------------------------------------------------------------------+
-| OpenMP directives in concurrent loop regions                | :none:`unclaimed`         | :none:`unclaimed`         |                                                                          |
+| OpenMP directives in concurrent loop regions                | :good:`done`              | :none:`unclaimed`         | https://github.com/llvm/llvm-project/pull/125621                         |
 +-------------------------------------------------------------+---------------------------+---------------------------+--------------------------------------------------------------------------+
-| atomics constructs on concurrent loop regions               | :none:`unclaimed`         | :none:`unclaimed`         |                                                                          |
+| atomics constructs on concurrent loop regions               | :good:`done`              | :none:`unclaimed`         | https://github.com/llvm/llvm-project/pull/125621                         |
 +-------------------------------------------------------------+---------------------------+---------------------------+--------------------------------------------------------------------------+
 | Loop construct with DO CONCURRENT                           | :none:`unclaimed`         | :none:`unclaimed`         |                                                                          |
 +-------------------------------------------------------------+---------------------------+---------------------------+--------------------------------------------------------------------------+
@@ -456,9 +456,7 @@ implementation.
 +-------------------------------------------------------------+---------------------------+---------------------------+--------------------------------------------------------------------------+
 | map-type modifiers in arbitrary position                    | :none:`unclaimed`         | :none:`unclaimed`         |                                                                          |
 +-------------------------------------------------------------+---------------------------+---------------------------+--------------------------------------------------------------------------+
-| atomic constructs in loop region                            | :none:`unclaimed`         | :none:`unclaimed`         |                                                                          |
-+-------------------------------------------------------------+---------------------------+---------------------------+--------------------------------------------------------------------------+
-| Lift nesting restriction on concurrent loop                 | :none:`unclaimed`         | :none:`unclaimed`         |                                                                          |
+| Lift nesting restriction on concurrent loop                 | :good:`done`              | :none:`unclaimed`         | https://github.com/llvm/llvm-project/pull/125621                         |
 +-------------------------------------------------------------+---------------------------+---------------------------+--------------------------------------------------------------------------+
 | priority clause for target constructs                       | :none:`unclaimed`         | :none:`unclaimed`         |                                                                          |
 +-------------------------------------------------------------+---------------------------+---------------------------+--------------------------------------------------------------------------+