add sqlite_dbstat tag for the DBSTAT virtual table

Used to gather statistics information about table disk usage.

sqlite3_opt_dbstat.go

@@ -0,0 +1,15 @@
+// Copyright (C) 2025 Yasuhiro Matsumoto <mattn.jp@gmail.com>.
+// Copyright (C) 2025 Jakob Borg <jakob@kastelo.net>.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+//go:build sqlite_dbstat
+// +build sqlite_dbstat
+
+package sqlite3
+
+/*
+#cgo CFLAGS: -DSQLITE_ENABLE_DBSTAT_VTAB
+*/
+import "C"