[clang] [C++20] [Modules] [Itanium ABI] Generate the vtable in the module unit of dynamic classes (PR #75912)

[Chuanqi Xu via cfe-commits]

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@@ -318,6 +318,9 @@ namespace {
       if (Diags.hasUnrecoverableErrorOccurred())
         return;
 
+      if (RD->shouldEmitInExternalSource())
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ChuanqiXu9 wrote:

Done. I don't mind doing it really. But what I confuse is, it looks there are a lot of codes in CodeGen to decide whether or not to emit the vtable. So it looks not like a pure Sema job to me.

https://github.com/llvm/llvm-project/pull/75912