fix PR9015, a crash linking recursive metadata.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124099 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Linker/linkmdnode.ll b/test/Linker/linkmdnode.ll
index be74550..5f11580 100644
--- a/test/Linker/linkmdnode.ll
+++ b/test/Linker/linkmdnode.ll
@@ -10,3 +10,4 @@
   %x = call i8 @llvm.something(metadata !21)
   ret void
 }
+