Description:
------------
Generated column support was added with SQLite version 3.31.0 (2020-01-22).
Php does not yet support this version and with it the generated column syntax.

I'd like to propose an update to the sqlite extension to allow for the generated column syntax as described in https://sqlite.org/gencol.html.
Creating an (in-memory) sqlite database with `GENERATED ALWAYS AS` sql now gives a syntax error.

Test script:
---------------
<?php
$db = new \PDO('sqlite::memory:');
$sql = <<<SQL
CREATE TABLE t1(
   a INTEGER PRIMARY KEY,
   b INT,
   c TEXT,
   d INT GENERATED ALWAYS AS (a*abs(b)) VIRTUAL,
   e TEXT GENERATED ALWAYS AS (substr(c,b,b+1)) STORED
);
SQL;
$result = $db->exec($sql);
var_dump($result);
var_dump($db->errorInfo());