[clang] [clang][Sema] Propagate qualifiers during derived-to-base conversion (PR #127824)

[Aaron Ballman via cfe-commits]

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@@ -0,0 +1,34 @@
+// RUN: %clang_cc1 -std=c++20 -fsyntax-only -ast-dump %s | FileCheck %s
+
+// Ensure volatile is preserved during derived-to-base conversion. 
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AaronBallman wrote:

I think we should add more test coverage. 1) `const`, 2) `const volatile`, 3) `address_space`, 4) `_Atomic` 5) maybe pointer authentication? restrict?

https://github.com/llvm/llvm-project/pull/127824