IRGen: Add more tests for dll attributes

llvm-svn: 209596
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index d7b5ba4..1501be8 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -5056,7 +5056,8 @@
   // dllimport globals without explicit storage class are treated as extern. We
   // have to change the storage class this early to get the right DeclContext.
   if (SC == SC_None && !DC->isRecord() &&
-      hasParsedAttr(S, D, AttributeList::AT_DLLImport))
+      hasParsedAttr(S, D, AttributeList::AT_DLLImport) &&
+      !hasParsedAttr(S, D, AttributeList::AT_DLLExport))
     SC = SC_Extern;
 
   DeclContext *OriginalDC = DC;