release/19.x: [Clang] Consider outer instantiation scopes for constraint normalization

Backport 227afac

Author: zyn0217

clang/lib/Sema/SemaConcept.cpp

@@ -967,7 +967,7 @@ static const Expr *SubstituteConstraintExpressionWithoutSatisfaction(
   // parameters that the surrounding function hasn't been instantiated yet. Note
   // this may happen while we're comparing two templates' constraint
   // equivalence.
-  LocalInstantiationScope ScopeForParameters(S);
+  LocalInstantiationScope ScopeForParameters(S, /*CombineWithOuterScope=*/true);
   if (auto *FD = DeclInfo.getDecl()->getAsFunction())
     for (auto *PVD : FD->parameters()) {
       if (!PVD->isParameterPack()) {

clang/test/SemaTemplate/concepts-out-of-line-def.cpp

@@ -622,3 +622,19 @@ void A<T>::method(Ts&... ts)
   } {}
 
 }
+
+namespace GH114685 {
+
+template <typename T> struct ptr {
+  template <typename U>
+  friend ptr<U> make_item(auto &&args)
+    requires(sizeof(args) > 1);
+};
+
+template <typename U>
+ptr<U> make_item(auto &&args)
+  requires(sizeof(args) > 1) {}
+
+ptr<char> p;
+
+} // namespace GH114685