Set the unnamed_addr only when we're creating a new GV in the dest module.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128507 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index 5aa06ab..f372db2 100644
--- a/lib/Linker/LinkModules.cpp
+++ b/lib/Linker/LinkModules.cpp
@@ -505,6 +505,7 @@
                            SGV->getType()->getAddressSpace());
       // Propagate alignment, visibility and section info.
       CopyGVAttributes(NewDGV, SGV);
+      NewDGV->setUnnamedAddr(SGV->hasUnnamedAddr());
 
       // If the LLVM runtime renamed the global, but it is an externally visible
       // symbol, DGV must be an existing global with internal linkage.  Rename