[clang] [Clang][Sema] Fix lookup of dependent operator= outside of complete-class contexts (PR #91498)

[Erich Keane via cfe-commits]

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@@ -1269,19 +1269,19 @@ struct FindLocalExternScope {
 };
 } // end anonymous namespace
 
+static bool isDependentAssignmentOperator(DeclarationName Name,
+                                          DeclContext *LookupContext) {
+  auto *LookupRecord = dyn_cast_if_present<CXXRecordDecl>(LookupContext);
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erichkeane wrote:

```suggestion
  const auto *LookupRecord = dyn_cast_if_present<CXXRecordDecl>(LookupContext);
```

https://github.com/llvm/llvm-project/pull/91498