Fix for potential issue related to replacing CheckMaps with values.

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index 062b5ae7ace247dc6a38891952d77c0f827c7143..3701ec07fdae4f68a532bea00aa37eea4d062b2d 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -689,6 +689,9 @@ void HInstruction::PrintTo(StringStream* stream) {
   if (CheckFlag(HValue::kHasNoObservableSideEffects)) {
     stream->Add(" [noOSE]");
   }
+  if (CheckFlag(HValue::kIsDead)) {
+    stream->Add(" [dead]");
+  }
 }