[clang] [Clang] Implement C++26’s P2893R3 ‘Variadic friends’ (PR #101448)

[via cfe-commits]

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@@ -3800,7 +3800,8 @@ class Sema final : public SemaBase {
                                    const ParsedAttributesView &DeclAttrs,
                                    MultiTemplateParamsArg TemplateParams,
                                    bool IsExplicitInstantiation,
-                                   RecordDecl *&AnonRecord);
+                                   RecordDecl *&AnonRecord,
+                                   SourceLocation FriendEllipsisLoc = {});
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cor3ntin wrote:

```suggestion
                                   SourceLocation EllipsisLoc = {});
```

https://github.com/llvm/llvm-project/pull/101448