[clang] [Clang][Sema] Diagnose friend declarations with enum elaborated-type-specifier in all language modes (PR #80171)

[Krystian Stasiowski via cfe-commits]

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@@ -17534,79 +17534,6 @@ Decl *Sema::BuildStaticAssertDeclaration(SourceLocation StaticAssertLoc,
   return Decl;
 }
 
-/// Perform semantic analysis of the given friend type declaration.
-///
-/// \returns A friend declaration that.
-FriendDecl *Sema::CheckFriendTypeDecl(SourceLocation LocStart,
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sdkrystian wrote:

@cor3ntin We call `CheckFriendTypeDecl` from two places: `Sema::ActOnFriendTypeDecl`, and `TemplateDeclInsantiator::VisitFriendDecl`. However, the only thing that `CheckFriendTypeDecl` does during instantiation is call `FriendDecl::Create` -- the other checks are only done when initially parsing the declaration.  


https://github.com/llvm/llvm-project/pull/80171