[clang] Suppress noreturn warning if last statement in a function is a throw (PR #145166)

[Erich Keane via cfe-commits]

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@@ -2434,9 +2434,12 @@ Sema::PopFunctionScopeInfo(const AnalysisBasedWarnings::Policy *WP,
     OpenMP().popOpenMPFunctionRegion(Scope.get());
 
   // Issue any analysis-based warnings.
-  if (WP && D)
+  if (WP && D) {
+    if (auto *FD = dyn_cast<FunctionDecl>(D)) {
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erichkeane wrote:

Instead of doing the cast here, can we have `inferNoReturnAttr` just take `Decl`, and early-exist if the cast isn't valid?  Cleans this up a little.

Additionally, this is a case where you'd have to skip curley braces per coding standard.

https://github.com/llvm/llvm-project/pull/145166