[clang] [llvm] Ast importer visitors (PR #138838)

[Balázs Kéri via llvm-commits]

================
@@ -1609,6 +1609,12 @@ static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                      CXXMethodDecl *Method1,
                                      CXXMethodDecl *Method2) {
+  if (!Method1 && !Method2) {
+    return true;
+  }
+  if (!Method1 || !Method2) {
+    return false;
+  }
----------------
balazske wrote:

```suggestion
  if (!Method1 && !Method2)
    return true;
  if (!Method1 || !Method2)
    return false;
```

https://github.com/llvm/llvm-project/pull/138838