[clang-tools-extra] [clang-tidy] Allow type-generic builtins in pro-type-vararg check (PR #178656)

[Victor Chernyakin via cfe-commits]

================
@@ -178,6 +178,15 @@ void ProTypeVarargCheck::check(const MatchFinder::MatchResult &Result) {
   if (const auto *Matched = Result.Nodes.getNodeAs<CallExpr>("callvararg")) {
     if (hasSingleVariadicArgumentWithValue(Matched, 0))
       return;
+
+    // Skip builtins with custom type checking - they use variadics as an
+    // implementation detail to accept multiple types, not for C-style varargs.
+    if (const auto *FD = Matched->getDirectCallee())
+      if (const unsigned BuiltinID = FD->getBuiltinID();
+          BuiltinID &&
+          Result.Context->BuiltinInfo.hasCustomTypechecking(BuiltinID))
----------------
localspook wrote:

Now that we have this check, can we remove some of the entries from the `AllowedVariadics` list? Can we remove the list entirely?

https://github.com/llvm/llvm-project/pull/178656