work around missing _v2 functions on old libsqlite3 versions

Missing sqlite3_next_stmt is still a problem, but harder to work
around.

collects/db/private/sqlite3/ffi.rkt

@@ -25,6 +25,13 @@
 (define-sqlite sqlite3_libversion_number
   (_fun -> _int))
 
+(define-sqlite sqlite3_open
+  (_fun (filename ignored-flags) ::
+        (filename : _bytes)
+        (db : (_ptr o _sqlite3_database))
+        -> (result : _int)
+        -> (values db result)))
+
 (define-sqlite sqlite3_open_v2
   (_fun (filename flags) ::
         (filename : _bytes)
@@ -32,7 +39,8 @@
         (flags : _int)
         (vfs : _pointer = #f)
         -> (result : _int)
-        -> (values db result)))
+        -> (values db result))
+  #:fail (lambda () sqlite3_open))
 
 (define-sqlite sqlite3_close
   (_fun _sqlite3_database
@@ -49,6 +57,16 @@
     (ptr-set! rawcopy _byte n 0)
     copy))
 
+(define-sqlite sqlite3_prepare
+  (_fun (db sql) ::
+        (db : _sqlite3_database)
+        (sql-buffer : _bytes = (copy-buffer sql))
+        ((bytes-length sql-buffer) : _int)
+        (statement : (_ptr o _sqlite3_statement/null))
+        (tail : (_ptr o _bytes)) ;; points into sql-buffer (atomic-interior)
+        -> (result : _int)
+        -> (values result statement (and tail (positive? (bytes-length tail))))))
+
 (define-sqlite sqlite3_prepare_v2
   (_fun (db sql) ::
         (db : _sqlite3_database)
@@ -58,7 +76,8 @@
         (statement : (_ptr o _sqlite3_statement/null))
         (tail : (_ptr o _bytes)) ;; points into sql-buffer (atomic-interior)
         -> (result : _int)
-        -> (values result statement (and tail (positive? (bytes-length tail))))))
+        -> (values result statement (and tail (positive? (bytes-length tail)))))
+  #:fail (lambda () sqlite3_prepare))
 
 (define-sqlite sqlite3_finalize
   (_fun _sqlite3_statement