[clang] Reapply "[clang] Fix name lookup for dependent bases" (PR #118003)

[Yanzuo Liu via cfe-commits]

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@@ -3599,7 +3599,7 @@ <h2 id="cxxdr">C++ defect report implementation status</h2>
     <td><a href="https://cplusplus.github.io/CWG/issues/591.html">591</a></td>
     <td>CD4</td>
     <td>When a dependent base class is the current instantiation</td>
-    <td class="none" align="center">No</td>
+    <td class="none" align="center">Yes</td>
----------------
zwuis wrote:

```suggestion
    <td class="unreleased" align="center">Clang 20</td>
```


https://github.com/llvm/llvm-project/pull/118003