Fix errant fallthrough in the generation of the lifetime markers.
Found by Alexander Kornienko.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174207 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 393a6be..9bd6ae6 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5170,6 +5170,7 @@
       Res = DAG.getNode(Opcode, dl, MVT::Other, Ops, 2);
       DAG.setRoot(Res);
     }
+    return 0;
   }
   case Intrinsic::invariant_start:
     // Discard region information.