[clang] [Clang] Avoid assertion failure for initialized extern aliases (PR #223124)

[Aaron Ballman via cfe-commits]

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@@ -594,6 +590,11 @@ features cannot lower the translation-unit ABI level;
   written after the declarator-id, where it appertains to the declared entity
   rather than to a declarator chunk. (#GH196982, #GH111463)
 
+- Fixed an assertion failure when the `alias` attribute was applied to an
+  `extern` variable with an initializer. Static data members declared with
+  `alias` are now correctly diagnosed as definitions when followed by an
+  out-of-line definition.
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AaronBallman wrote:

```suggestion
  out-of-line definition. (#GH204762)
```
This will automatically link to the issue being resolved.

https://github.com/llvm/llvm-project/pull/223124