MIPS: Fix LStoreKeyed error when tracing instruction.

src/mips/lithium-mips.cc

Index: src/mips/lithium-mips.cc
diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc
index 60188a22700146d6a91e5eb13da5a9e71fd3a5ae..2247e7c3ef0f2af28d9b92e09b9b5a8698fc31e0 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -409,7 +409,14 @@ void LStoreKeyed::PrintDataTo(StringStream* stream) {
   } else {
     stream->Add("] <- ");
   }
-  value()->PrintTo(stream);
+
+  if (value() == NULL) {
+    ASSERT(hydrogen()->IsConstantHoleStore() &&
+           hydrogen()->value()->representation().IsDouble());
+    stream->Add("<the hole(nan)>");
+  } else {
+    value()->PrintTo(stream);
+  }
 }