Remove ASSERT_SIZE in favor of the safer DEFINE_SIZE_STATIC
diff --git a/src/hb-open-file-private.hh b/src/hb-open-file-private.hh
index 53e947a..d8d70e5 100644
--- a/src/hb-open-file-private.hh
+++ b/src/hb-open-file-private.hh
@@ -139,8 +139,9 @@
   LongOffsetLongArrayOf<OffsetTable>
 		table;		/* Array of offsets to the OffsetTable for each font
 				 * from the beginning of the file */
+  public:
+  DEFINE_SIZE_STATIC (12);
 };
-ASSERT_SIZE (TTCHeaderVersion1, 12);
 
 struct TTCHeader
 {