More debug output.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153571 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 4062ae9..49f0431 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -4697,7 +4697,8 @@
     const AllocaInst *AI = dyn_cast<AllocaInst>(V);
     // Don't handle byval struct arguments or VLAs, for example.
     if (!AI) {
-      DEBUG(dbgs() << "Dropping debug location info for:\n\t" << DI << "\n");
+      DEBUG(dbgs() << "Dropping debug location info for:\n  " << DI << "\n");
+      DEBUG(dbgs() << "  Last seen at:\n    " << *V << "\n");
       return 0;
     }
     DenseMap<const AllocaInst*, int>::iterator SI =