X64: Fix bad value in stack layout constants.

src/spaces.h

Index: src/spaces.h
diff --git a/src/spaces.h b/src/spaces.h
index 0538c5f36676df57fa46f8bc384f34e37acb510d..8ce807fcd48b4ee571463d1057ed803c1933f50a 100644
--- a/src/spaces.h
+++ b/src/spaces.h
@@ -1270,7 +1270,7 @@ class FreeListNode: public HeapObject {
   inline void set_next(Address next);
 
  private:
-  static const int kNextOffset = Array::kHeaderSize;
+  static const int kNextOffset = POINTER_SIZE_ALIGN(ByteArray::kHeaderSize);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(FreeListNode);
 };
@@ -1304,7 +1304,8 @@ class OldSpaceFreeList BASE_EMBEDDED {
  private:
   // The size range of blocks, in bytes. (Smaller allocations are allowed, but
   // will always result in waste.)
-  static const int kMinBlockSize = Array::kHeaderSize + kPointerSize;
+  static const int kMinBlockSize =
+      POINTER_SIZE_ALIGN(ByteArray::kHeaderSize) + kPointerSize;
   static const int kMaxBlockSize = Page::kMaxHeapObjectSize;
 
   // The identity of the owning space, for building allocation Failure