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

[Shafik Yaghmour via cfe-commits]

================
@@ -3107,8 +3107,12 @@ Sema::PerformObjectMemberConversion(Expr *From,
                                    /*IgnoreAccess=*/true))
     return ExprError();
 
-  return ImpCastExprToType(From, DestType, CK_UncheckedDerivedToBase,
-                           VK, &BasePath);
+  Qualifiers FromTypeQuals = FromType.getQualifiers();
----------------
shafik wrote:

Maybe add a quote from https://eel.is/c++draft/basic.type.qualifier#def:object,volatile

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