[clang] Improve C string null terminator diagnostics (PR #190411)

[Eli Friedman via cfe-commits]

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@@ -1141,6 +1141,97 @@ static bool ProcessFormatStringLiteral(const Expr *FormatExpr,
   return false;
 }
 
+static StringRef getSimpleLibraryFunctionName(const FunctionDecl *FD) {
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efriedma-quic wrote:

We generally prefer to check BuiltinIDs instead of directly examining the name; names are complicated to analyze.

https://github.com/llvm/llvm-project/pull/190411