[ticket/16538] Add identifiers quoting

If reserved word is used as identifier, it must be quoted.
If alias is used elsewhere in SQL statement, it must be quoted.

PHPBB3-16535
PHPBB3-16538

phpBB/phpbb/db/driver/mssql_base.php

@@ -76,4 +76,12 @@ abstract class mssql_base extends \phpbb\db\driver\driver
 	{
 		return $data;
 	}
+
+	/**
+	* {@inheritDoc}
+	*/
+	function sql_quote($msg)
+	{
+		return '"' . $msg . '"';
+	}
 }