Fix a bug when pretty-printing DW_OP_deref.

llvm-svn: 223493
diff --git a/llvm/lib/IR/DebugInfo.cpp b/llvm/lib/IR/DebugInfo.cpp
index bf3bb8a..c6e4c87 100644
--- a/llvm/lib/IR/DebugInfo.cpp
+++ b/llvm/lib/IR/DebugInfo.cpp
@@ -1415,6 +1415,9 @@
       OS << " offset=" << Offset << ", size=" << Size;
       break;
     }
+    case DW_OP_deref:
+      // No arguments.
+      break;
     default:
       // Else bail out early. This may be a line table entry.
       OS << "Unknown]";