src: use 24 as default for kHeaderSize

PR-URL: #330
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>

Author: mmarchini

src/llv8-constants.cc

@@ -501,7 +501,7 @@ void DescriptorArray::Load() {
   kFirstIndex = LoadOptionalConstant({"prop_idx_first"}, 0);
   kSize = LoadConstant({"prop_desc_size"});
   kHeaderSize = LoadOptionalConstant(
-      {"class_DescriptorArray__header_size__uintptr_t"}, 0);
+      {"class_DescriptorArray__header_size__uintptr_t"}, 24);
 }
 
 

src/llv8-inl.h

@@ -889,7 +889,7 @@ inline T DescriptorArray::Get(int index, int64_t offset) {
   if (v8()->descriptor_array()->kFirstIndex.Loaded()) {
     return FixedArray::Get<T>(
         *(v8()->descriptor_array()->kFirstIndex) + index + offset, err);
-  } else if (v8()->descriptor_array()->kHeaderSize.Loaded()) {
+  } else if (v8()->descriptor_array()->kHeaderSize.Check()) {
     index *= v8()->common()->kPointerSize;
     index += *(v8()->descriptor_array()->kHeaderSize);
     index += (v8()->common()->kPointerSize * offset);