[clang] [clang][NFC] Refactor `Sema::TemplateDeductionResult` (PR #81398)

[Erich Keane via cfe-commits]

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@@ -11445,11 +11452,16 @@ static void DiagnoseBadDeduction(Sema &S, NamedDecl *Found, Decl *Templated,
   (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) ||
   (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) ||
   (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>());
-  switch (DeductionFailure.Result) {
-  case Sema::TDK_Success:
-    llvm_unreachable("TDK_success while diagnosing bad deduction");
+  switch (DeductionFailure.getResult()) {
+  case TemplateDeductionResult::Success:
+    llvm_unreachable(
+        "TemplateDeductionResult::Success while diagnosing bad deduction");
+  case TemplateDeductionResult::Invalid:
+  case TemplateDeductionResult::NonDependentConversionFailure:
+  case TemplateDeductionResult::AlreadyDiagnosed:
+    return;
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erichkeane wrote:

Cool.  It'll be interesting to see if we ever end up here, and the assert message is good enough we can figure out what to do pretty easily based on bug reports.  Thanks!

https://github.com/llvm/llvm-project/pull/81398