VectorICs: megamorphic keyed loads in crankshaft don't need a vector.

src/hydrogen-instructions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HYDROGEN_INSTRUCTIONS_H_
 #define V8_HYDROGEN_INSTRUCTIONS_H_
 
 #include <cstring>
 #include <iosfwd>
 
@@ skipping 6698 matching lines @@
   HValue* object() const { return OperandAt(0); }
   HValue* key() const { return OperandAt(1); }
   HValue* context() const { return OperandAt(2); }
   InlineCacheState initialization_state() const {
     return initialization_state_;
   }
   FeedbackVectorICSlot slot() const { return slot_; }
   Handle<TypeFeedbackVector> feedback_vector() const {
     return feedback_vector_;
   }
-  bool HasVectorAndSlot() const { return FLAG_vector_ics; }
+  bool HasVectorAndSlot() const {
+    DCHECK(!FLAG_vector_ics || initialization_state_ == MEGAMORPHIC ||
+           feedback_vector_.is_null());
+    return !feedback_vector_.is_null();
+  }
   void SetVectorAndSlot(Handle<TypeFeedbackVector> vector,
                         FeedbackVectorICSlot slot) {
     DCHECK(FLAG_vector_ics);
     feedback_vector_ = vector;
     slot_ = slot;
   }
 
   std::ostream& PrintDataTo(std::ostream& os) const OVERRIDE;  // NOLINT
 
   Representation RequiredInputRepresentation(int index) OVERRIDE {
@@ skipping 1143 matching lines @@
 };
 
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_