[clang] [clang] fix some places where used decls were not marked as referenced (PR #191848)

[Erich Keane via cfe-commits]

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@@ -3795,6 +3795,10 @@ QualType Sema::CheckTemplateIdType(ElaboratedTypeKeyword Keyword,
                                 /*UpdateArgsWithConversions=*/true))
     return QualType();
 
+  // Diagnose uses of this template.
+  (void)DiagnoseUseOfDecl(Template, TemplateLoc);
+  MarkAnyDeclReferenced(TemplateLoc, Template, /*OdrUse=*/false);
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erichkeane wrote:

I'm not saying we should avoid calling it, quite the opposite.  I'm just saying we need to find some way to validate that it is called so the call doesn't get lost later. I've found claude can be good at this sort of thing.

https://github.com/llvm/llvm-project/pull/191848