[clang] [llvm] [ThinLTO] Support dead RTTI data elimination under -fno-split-lto-unit (PR #126336)

[Teresa Johnson via cfe-commits]

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@@ -1187,8 +1191,10 @@ Error LTO::run(AddStreamFn AddStream, FileCache Cache) {
       return PrevailingType::Unknown;
     return It->second;
   };
-  computeDeadSymbolsWithConstProp(ThinLTO.CombinedIndex, GUIDPreservedSymbols,
-                                  isPrevailing, Conf.OptLevel > 0);
+
+  if (!RegularLTO.ModsWithSummaries.empty())
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teresajohnson wrote:

Add comment about new condition

https://github.com/llvm/llvm-project/pull/126336