update V8 to r5532 as required by WebKit r68651

Change-Id: I5f75eeffbf64b30dd5080348528d277f293490ad
diff --git a/src/spaces.h b/src/spaces.h
index 9ffa940..94e0cd2 100644
--- a/src/spaces.h
+++ b/src/spaces.h
@@ -243,8 +243,10 @@
   static const int kPageHeaderSize = kPointerSize + kPointerSize + kIntSize +
     kIntSize + kPointerSize;
 
-  // The start offset of the object area in a page.
-  static const int kObjectStartOffset = MAP_POINTER_ALIGN(kPageHeaderSize);
+  // The start offset of the object area in a page. Aligned to both maps and
+  // code alignment to be suitable for both.
+  static const int kObjectStartOffset =
+      CODE_POINTER_ALIGN(MAP_POINTER_ALIGN(kPageHeaderSize));
 
   // Object area size in bytes.
   static const int kObjectAreaSize = kPageSize - kObjectStartOffset;