Avoid one repeated property lookup when computing load ICs.

src/lookup.h

Index: src/lookup.h
diff --git a/src/lookup.h b/src/lookup.h
index c96b2d11dd640d7044b635a29fcb4325f5ae672a..5593188010612d149c1701b0eb10985f904a4805 100644
--- a/src/lookup.h
+++ b/src/lookup.h
@@ -99,7 +99,7 @@ class LookupIterator V8_FINAL BASE_EMBEDDED {
     return Handle<T>::cast(maybe_holder_.ToHandleChecked());
   }
   Handle<JSReceiver> GetRoot() const;
-  bool HolderIsReceiver() const;
+  bool HolderIsReceiverOrHiddenPrototype() const;
 
   /* Dynamically reduce the trapped types. */
   void skip_interceptor() {
@@ -127,15 +127,20 @@ class LookupIterator V8_FINAL BASE_EMBEDDED {
     ASSERT(has_property_);
     return property_kind_;
   }
+  PropertyEncoding property_encoding() const {
+    ASSERT(has_property_);
+    return property_encoding_;
+  }
   PropertyDetails property_details() const {
     ASSERT(has_property_);
     return property_details_;
   }
-  int descriptor_number() const {
-    ASSERT(has_property_);
-    ASSERT_EQ(DESCRIPTOR, property_encoding_);
-    return number_;
+  bool IsConfigurable() const { return !property_details().IsDontDelete(); }
+  Representation representation() const {
+    return property_details().representation();
   }
+  FieldIndex GetFieldIndex() const;
+  Handle<PropertyCell> GetPropertyCell() const;
   Handle<Object> GetAccessors() const;
   Handle<Object> GetDataValue() const;
   void WriteDataValue(Handle<Object> value);
@@ -170,6 +175,16 @@ class LookupIterator V8_FINAL BASE_EMBEDDED {
   bool check_access_check() const {
     return (configuration_ & CHECK_ACCESS_CHECK) != 0;
   }
+  int descriptor_number() const {
+    ASSERT(has_property_);
+    ASSERT_EQ(DESCRIPTOR, property_encoding_);
+    return number_;
+  }
+  int dictionary_entry() const {
+    ASSERT(has_property_);
+    ASSERT_EQ(DICTIONARY, property_encoding_);
+    return number_;
+  }
 
   Configuration configuration_;
   State state_;