Mark VTables and RTTI data linkonce_odr instead of weak_odr, with the exception of explicit template instantiations, which have to be weak_odr.

This fixes PR6996.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@124089 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGRTTI.cpp b/lib/CodeGen/CGRTTI.cpp
index 9f3571e..6e57f90 100644
--- a/lib/CodeGen/CGRTTI.cpp
+++ b/lib/CodeGen/CGRTTI.cpp
@@ -355,10 +355,10 @@
         return CodeGenModule::getVTableLinkage(RD);
     }
 
-    return llvm::GlobalValue::WeakODRLinkage;
+    return llvm::GlobalValue::LinkOnceODRLinkage;
   }
 
-  return llvm::GlobalValue::WeakODRLinkage;
+  return llvm::GlobalValue::LinkOnceODRLinkage;
 }
 
 // CanUseSingleInheritance - Return whether the given record decl has a "single, 
@@ -640,7 +640,7 @@
                           /*ForRTTI*/ true, /*ForDefinition*/ true);
   else if (Hidden || 
            (CGM.getCodeGenOpts().HiddenWeakVTables &&
-            Linkage == llvm::GlobalValue::WeakODRLinkage)) {
+            Linkage == llvm::GlobalValue::LinkOnceODRLinkage)) {
     GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
   }
   GV->setUnnamedAddr(true);