Add hb_array<>() specialization for UnsizedArrayOf

Related https://github.com/harfbuzz/harfbuzz/issues/1301

src/hb-aat-layout-trak-table.hh

@@ -55,7 +55,7 @@ struct TrackTableEntry
 			unsigned int index,
 			unsigned int nSizes) const
   {
-    return hb_array ((base+valuesZ).arrayZ, nSizes)[index];
+    return hb_array (base+valuesZ, nSizes)[index];
   }
 
   public:

src/hb-open-file.hh

@@ -330,7 +330,7 @@ struct ResourceTypeRecord
   inline const ResourceRecord& get_resource_record (unsigned int i,
 						    const void *type_base) const
   {
-    return hb_array ((type_base+resourcesZ).arrayZ, get_resource_count ())[i];
+    return hb_array (type_base+resourcesZ, get_resource_count ())[i];
   }
 
   inline bool sanitize (hb_sanitize_context_t *c,

src/hb-open-type.hh

@@ -385,6 +385,14 @@ struct UnsizedArrayOf
   public:
   DEFINE_SIZE_ARRAY (0, arrayZ);
 };
+} /* namespace OT */
+template <typename T>
+hb_array_t<T> hb_array (OT::UnsizedArrayOf<T> &array, unsigned int len)
+{ return hb_array (array.arrayZ, len); }
+template <typename T>
+hb_array_t<const T> hb_array (const OT::UnsizedArrayOf<T> &array, unsigned int len)
+{ return hb_array (array.arrayZ, len); }
+namespace OT {
 
 /* Unsized array of offset's */
 template <typename Type, typename OffsetType, bool has_null=true>

src/hb-ot-color-cpal-table.hh

@@ -55,7 +55,7 @@ struct CPALV1Tail
   {
     if (!paletteFlagsZ) return HB_OT_COLOR_PALETTE_FLAG_DEFAULT;
     return (hb_ot_color_palette_flags_t) (uint32_t)
-	   hb_array ((base+paletteFlagsZ).arrayZ, palette_count)[palette_index];
+	   hb_array (base+paletteFlagsZ, palette_count)[palette_index];
   }
 
   inline unsigned int
@@ -64,7 +64,7 @@ struct CPALV1Tail
 		       unsigned int palette_count) const
   {
     if (!paletteLabelsZ) return HB_NAME_ID_INVALID;
-    return hb_array ((base+paletteLabelsZ).arrayZ, palette_count)[palette_index];
+    return hb_array (base+paletteLabelsZ, palette_count)[palette_index];
   }
 
   inline unsigned int
@@ -73,7 +73,7 @@ struct CPALV1Tail
 		     unsigned int color_count) const
   {
     if (!colorLabelsZ) return HB_NAME_ID_INVALID;
-    return hb_array ((base+colorLabelsZ).arrayZ, color_count)[color_index];
+    return hb_array (base+colorLabelsZ, color_count)[color_index];
   }
 
   public: