Migrate SQLite to use exceptions instead of returning FALSE

Includes forward-compatible checks for PHP 9.0, when this will be the default
See https://wiki.php.net/rfc/sqlite3_exceptions
Implements #52

src/main/php/rdbms/sqlite3/SQLite3Connection.class.php

@@ -103,7 +103,9 @@ public function connect($reconnect= false) {
 
     try {
       $this->handle= new SQLite3($database, SQLITE3_OPEN_READWRITE | SQLITE3_OPEN_CREATE);
+      PHP_VERSION_ID >= 90000 || $this->handle->enableExceptions(true);
     } catch (Exception $e) {
+      $this->handle= false;
       throw new SQLConnectException($e->getMessage().': '.$database, $this->dsn);
     }
 
@@ -160,16 +162,17 @@ public function identity($field= null) {
   protected function query0($sql, $buffered= true) {
     $this->handle instanceof SQLite3 || $this->connections->establish($this);
 
-    $result= $this->handle->query($sql);
-    if (false === $result) {
-      $e= new SQLStatementFailedException(
+    try {
+      $result= $this->handle->query($sql);
+    } catch (Exception $e) {
+      throw new SQLStatementFailedException(
         'Statement failed: '.$this->handle->lastErrorMsg().' @ '.$this->dsn->getDatabase(),
         $sql, 
         $this->handle->lastErrorCode()
       );
-      \xp::gc(__FILE__);
-      throw $e;
-    } else if ($result->numColumns()) {
+    }
+
+    if ($result->numColumns()) {
       return new SQLite3ResultSet($result);
     } else {
       return new QuerySucceeded($this->handle->changes());