[clang] [CLANG] Enable alignas after GNU attributes (PR #133107)

[via cfe-commits]

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@@ -296,6 +296,11 @@ StmtResult Parser::ParseStatementOrDeclarationAfterAttributes(
     goto Retry;
   }
 
+  case tok::kw_alignas: {
+    ParseAlignmentSpecifier(CXX11Attrs);
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DenisGZM wrote:

No, we don't. Аor statements alignas is still illegal:
```
error: 'alignas' attribute cannot be applied to a statement
    8 |   alignas(int) foo();
```

https://github.com/llvm/llvm-project/pull/133107