Fix unused variable bug in r7444.

src/type-info.cc

Index: src/type-info.cc
diff --git a/src/type-info.cc b/src/type-info.cc
index d73c618de9a3e2da12d4ad1fcf28dc6cceb6d293..4fd38fa45253098e4fa68d0c1450fdb4c286cc90 100644
--- a/src/type-info.cc
+++ b/src/type-info.cc
@@ -358,6 +358,8 @@ ZoneMapList* TypeFeedbackOracle::CollectReceiverTypes(int position,
 void TypeFeedbackOracle::SetInfo(int position, Object* target) {
   MaybeObject* maybe_result = dictionary_->AtNumberPut(position, target);
   Object* result;
+  USE(maybe_result);
+  USE(result);
   // Dictionary has been allocated with sufficient size for all elements.
   ASSERT(maybe_result->ToObject(&result));
   ASSERT(*dictionary_ == result);