[FOLD] add test and release note

Author: sdkrystian

clang/docs/ReleaseNotes.rst

@@ -693,6 +693,8 @@ Bug Fixes to C++ Support
   and (#GH88832).
 - Clang now defers all substitution into the exception specification of a function template specialization
   until the noexcept-specifier is instantiated.
+- Fix a crash when an implicitly declared ``operator==`` function with a trailing requires-clause has its
+  constraints compared to that of another declaration.
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^

clang/test/CXX/class/class.compare/class.compare.default/p4.cpp

@@ -161,3 +161,14 @@ struct non_constexpr_type {
 
 my_struct<non_constexpr_type> obj; // cxx2a-note {{in instantiation of template class 'GH61238::my_struct<GH61238::non_constexpr_type>' requested here}}
 }
+
+namespace Constrained {
+  template<typename T>
+  struct A {
+    std::strong_ordering operator<=>(const A&) const requires true = default;
+  };
+
+  bool f(A<int> a) {
+    return a != A<int>();
+  }
+}