add release note

Author: Backl1ght

clang/docs/ReleaseNotes.rst

@@ -694,6 +694,7 @@ Bug Fixes in This Version
 - Constant evaluation now correctly runs the destructor of a variable declared in
   the second clause of a C-style ``for`` loop. (#GH139818)
 - Fixed a bug with constexpr evaluation for structs containing unions in case of C++ modules. (#GH143168)
+- Fixed an infinite recursion about defaulted constexpr dtor. (#GH141789)
 
 Bug Fixes to Compiler Builtins
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