Add a comment about #339 research

Signed-off-by: William Desportes <williamdes@wdes.fr>

Author: williamdes

src/Statements/CreateStatement.php

@@ -47,6 +47,7 @@ class CreateStatement extends Statement
             4,
             'expr=',
         ),
+        // Used in `CREATE VIEW`
         'SQL SECURITY' => array(
             5,
             'var',