[clang] Update Catch missing format attributes (PR #106649)

[Budimir Aranđelović via cfe-commits]

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@@ -5506,16 +5509,13 @@ Sema::GetMissingFormatAttributes(Stmt *Body, const FunctionDecl *FDecl) {
     }
 
     // Get first argument index
-    unsigned FirstToCheck = [&]() -> unsigned {
+    int FirstToCheck = [&]() -> unsigned {
       if (!FDecl->isVariadic())
         return 0;
-      const auto *FirstToCheckArg =
-          dyn_cast<DeclRefExpr>(Args[NumArgs - 1]->IgnoreParenCasts());
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budimirarandjelovichtec wrote:

I removed dynamic cast to DeclRefAttr of last function argument. In C++ mode casting to DeclRefAttr resulted in unrecognizing argument type as va_list for several architectures and OS.

https://github.com/llvm/llvm-project/pull/106649