[clang] [Clang] Set `__cpp_explicit_this_parameter` (PR #107451)

[Erich Keane via cfe-commits]

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@@ -272,6 +272,8 @@ C++23 Feature Support
 
 - Extend lifetime of temporaries in mem-default-init for P2718R0. Clang now fully
   supports `P2718R0 Lifetime extension in range-based for loops <https://wg21.link/P2718R0>`_.
+  
+- ``__cpp_explicit_this_parameter`` is now defined. (#GH82780)
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erichkeane wrote:

As a nit, "is now defined to the value specified in the C++X specification." 

perhaps?

https://github.com/llvm/llvm-project/pull/107451