[clang] [clang] Fix static_cast bypassing access control (PR #132285)

[via cfe-commits]

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@@ -1572,13 +1571,12 @@ TryCastResult TryLValueToRValueCast(Sema &Self, Expr *SrcExpr,
 
   if (RefConv & Sema::ReferenceConversions::DerivedToBase) {
     Kind = CK_DerivedToBase;
-    CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
-                       /*DetectVirtual=*/true);
-    if (!Self.IsDerivedFrom(SrcExpr->getBeginLoc(), SrcExpr->getType(),
-                            R->getPointeeType(), Paths))
-      return TC_NotApplicable;
-
-    Self.BuildBasePathArray(Paths, BasePath);
+    if (Self.CheckDerivedToBaseConversion(FromType, ToType,
+                                          SrcExpr->getBeginLoc(), OpRange,
+                                          &BasePath, CStyle)) {
+      msg = 0;
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offsetof wrote:

Yes, `msg` defaults to `err_bad_cxx_cast_generic` but `CheckDerivedToBaseConversion` already emits a more specific diagnostic.

https://github.com/llvm/llvm-project/pull/132285