[clang] Make [[clang::lifetimebound]] work for expressions coming from default arguments (PR #112047)

[Utkarsh Saxena via cfe-commits]

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@@ -465,17 +466,27 @@ static void visitFunctionCallArguments(IndirectLocalPath &Path, Expr *Call,
   for (unsigned I = 0,
                 N = std::min<unsigned>(Callee->getNumParams(), Args.size());
        I != N; ++I) {
+    Expr *Arg = Args[I];
+    auto *DAE = dyn_cast<CXXDefaultArgExpr>(Arg);
+    if (DAE) {
+      Path.push_back(
+          {IndirectLocalPathEntry::DefaultArg, DAE, DAE->getParam()});
+      Arg = DAE->getExpr();
+    }
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usx95 wrote:

You can use `RevertToOldSizeRAII` to do the `pop_back` for you. This way you can write 
`if (auto *DAE = dyn_cast<CXXDefaultArgExpr>(Arg)) {...}`

https://github.com/llvm/llvm-project/pull/112047