[clang] [clang] disallow narrowing when matching template template parameters (PR #124313)

[Matheus Izvekov via cfe-commits]

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@@ -11682,6 +11683,7 @@ class Sema final : public SemaBase {
                         SmallVectorImpl<TemplateArgument> &SugaredConverted,
                         SmallVectorImpl<TemplateArgument> &CanonicalConverted,
                         CheckTemplateArgumentKind CTAK, bool PartialOrdering,
+                        bool PartialOrderingTTP,
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mizvekov wrote:

Ping, how may we proceed?

I don't think a good solution to this would come in this patch, as we have the same problem in multiple places, and this would add a lot of noise here.

We are due a refactor of these partial ordering functions, and I'd prefer to tackle that on a followup.

https://github.com/llvm/llvm-project/pull/124313