[turbofan] Fix various issues with --turbo-inlining enabled.

src/compiler/js-operator.h

Index: src/compiler/js-operator.h
diff --git a/src/compiler/js-operator.h b/src/compiler/js-operator.h
index 7883bfc9eb78efaf506acda035278c5d0510ef5e..172b584b43f509d2b7a8b438fdd574a2bf4b3128 100644
--- a/src/compiler/js-operator.h
+++ b/src/compiler/js-operator.h
@@ -24,7 +24,7 @@ class VectorSlotPair {
   VectorSlotPair(Handle<TypeFeedbackVector> vector, FeedbackVectorSlot slot)
       : vector_(vector), slot_(slot) {}
 
-  bool IsValid() const { return !vector_.is_null(); }
+  bool IsValid() const { return !vector_.is_null() && !slot_.IsInvalid(); }
 
   Handle<TypeFeedbackVector> vector() const { return vector_; }
   FeedbackVectorSlot slot() const { return slot_; }