Add a testcase for a recent regression.

Thanks to Bill Wendling for the original testcase.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180586 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/SemaCXX/linkage.cpp b/test/SemaCXX/linkage.cpp
index 6b73d59..13d295a 100644
--- a/test/SemaCXX/linkage.cpp
+++ b/test/SemaCXX/linkage.cpp
@@ -94,3 +94,12 @@
 
 // CHECK: define linkonce_odr i8* @_ZN5test21A1BILj0EE3fooEv(
 // CHECK: define linkonce_odr i8* @_ZN5test11A3fooILj0EEEPvv(
+
+namespace test5 {
+  struct foo {
+  };
+  extern "C" {
+    const foo bar[]  = {
+    };
+  }
+}