[clang] Fix Strong VTables Accidentally Emitted by #159856 (PR #200942)

[Patrick Simmons via cfe-commits]

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@@ -1849,6 +1849,9 @@ void CGOpenMPRuntime::emitAndRegisterVTable(CodeGenModule &CGM,
       CGM.EmitVTable(CXXRecord);
       CodeGenVTables VTables = CGM.getVTables();
       llvm::GlobalVariable *VTablesAddr = VTables.GetAddrOfVTable(CXXRecord);
+      // Must set VTables to weak since we're emitting them in multiple TUs now
+      if (VTablesAddr->hasExternalLinkage())
+        VTablesAddr->setLinkage(llvm::GlobalValue::WeakODRLinkage);
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linuxrocks123 wrote:

Moved after assertion (will push soon).  From `CodeGenModule::getVTableLinkage`, it looks like WeakODRLinkage is the correct linkage type to use for VTables that can't be discarded.

https://github.com/llvm/llvm-project/pull/200942