[clang] Adds a pseudonym to clang"s windows mangler... (PR #97792)

[via cfe-commits]

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@@ -1938,12 +1946,23 @@ void MicrosoftCXXNameMangler::mangleTemplateArgValue(QualType T,
         mangleNumber(V.getLValueOffset().getQuantity());
       } else if (!V.hasLValuePath()) {
         // FIXME: This can only happen as an extension. Invent a mangling.
-        break;
+        DiagnosticsEngine &Diags = Context.getDiags();
+        unsigned DiagID =
+            Diags.getCustomDiagID(DiagnosticsEngine::Error,
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memory-thrasher wrote:

Done. I couldn't stand to refactor just one piece of the class so I did all the "cannot mange * yet" errors.
@rnk 

https://github.com/llvm/llvm-project/pull/97792