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

src/hydrogen.h

Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index 97231a604c976076e6d6ecf74d4ce3f3e363f893..a4451d7a0891bc2a07d8b9f3117053b1c644886c 100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -2157,6 +2157,12 @@ class HOptimizedGraphBuilder : public HGraphBuilder, public AstVisitor {
   TestContext* inlined_test_context() const {
     return function_state()->test_context();
   }
+  Handle<SharedFunctionInfo> current_shared_info() const {
+    return current_info()->shared_info();
+  }
+  TypeFeedbackVector* current_feedback_vector() const {
+    return current_shared_info()->feedback_vector();
+  }
   void ClearInlinedTestContext() {
     function_state()->ClearInlinedTestContext();
   }