Add a missing break, from John Wiegley

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@126919 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ItaniumMangle.cpp b/lib/AST/ItaniumMangle.cpp
index 8474ea3..45653e6 100644
--- a/lib/AST/ItaniumMangle.cpp
+++ b/lib/AST/ItaniumMangle.cpp
@@ -2176,6 +2176,7 @@
       Diags.Report(DiagID);
       return;
     }
+    break;
   }
   }
 }