[llvm] [ThinLTO][WPD] Suppress WPD on a class if any superclass is visible in a shared library for index-based WPD (PR #131721)

[Mingming Liu via llvm-commits]

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@@ -1905,7 +1905,7 @@ Error LTO::runThinLTO(AddStreamFn AddStream, FileCache Cache,
     auto IsVisibleToRegularObj = [&](StringRef name) {
       auto It = GlobalResolutions->find(name);
       return (It == GlobalResolutions->end() ||
-              It->second.VisibleOutsideSummary);
+              It->second.VisibleOutsideSummary || It->second.ExportDynamic);
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mingmingl-llvm wrote:

done, and added test coverage for hybrid LTO. Regular LTO test coverage is not very meaningful, since without this change, the `VisibleOutsideSummary` bit suppresses devirtualization with `-Wl,--lto-whole-program-visibility -Wl,--lto-validate-all-vtables-have-type-infos` in lld

https://github.com/llvm/llvm-project/pull/131721