[config] Disable buffer serialize routines in HB_TINY

Part of https://github.com/harfbuzz/harfbuzz/issues/1652

src/hb-buffer-serialize.cc

@@ -28,8 +28,10 @@
 
 
 static const char *serialize_formats[] = {
+#ifndef HB_NO_BUFFER_SERIALIZE
   "text",
   "json",
+#endif
   nullptr
 };
 
@@ -85,10 +87,12 @@ hb_buffer_serialize_format_from_string (const char *str, int len)
 const char *
 hb_buffer_serialize_format_to_string (hb_buffer_serialize_format_t format)
 {
-  switch (format)
+  switch ((unsigned) format)
   {
+#ifndef HB_NO_BUFFER_SERIALIZE
     case HB_BUFFER_SERIALIZE_FORMAT_TEXT:	return serialize_formats[0];
     case HB_BUFFER_SERIALIZE_FORMAT_JSON:	return serialize_formats[1];
+#endif
     default:
     case HB_BUFFER_SERIALIZE_FORMAT_INVALID:	return nullptr;
   }
@@ -344,6 +348,10 @@ hb_buffer_serialize_glyphs (hb_buffer_t *buffer,
   if (buf_size)
     *buf = '\0';
 
+#ifdef HB_NO_BUFFER_SERIALIZE
+  return 0;
+#endif
+
   assert ((!buffer->len && buffer->content_type == HB_BUFFER_CONTENT_TYPE_INVALID) ||
 	  buffer->content_type == HB_BUFFER_CONTENT_TYPE_GLYPHS);
 
@@ -449,6 +457,10 @@ hb_buffer_deserialize_glyphs (hb_buffer_t *buffer,
     end_ptr = &end;
   *end_ptr = buf;
 
+#ifdef HB_NO_BUFFER_SERIALIZE
+  return false;
+#endif
+
   assert ((!buffer->len && buffer->content_type == HB_BUFFER_CONTENT_TYPE_INVALID) ||
 	  buffer->content_type == HB_BUFFER_CONTENT_TYPE_GLYPHS);
 

src/hb-config.hh

@@ -45,6 +45,7 @@
 #ifdef HB_LEAN
 #define HB_DISABLE_DEPRECATED
 #define HB_NO_ATEXIT
+#define HB_NO_BUFFER_SERIALIZE
 #define HB_NO_BITMAP
 #define HB_NO_CFF
 #define HB_NO_COLOR