Demonstrates that NULL parameters are handled incorrectly by the sql parser utils as of 2.3.4

This reverts commit 0b6a6aef.

fix :: operator in sql parser

[DBAL-78] Add support for native sql list support in positional queries through the introduction of two new constants:

* Doctrine\DBAL\Connection::PARAM_STR_ARRAY
* Doctrine\DBAL\Connection::PARAM_INT_ARRAY

Replacement of arrays only works in conjunction with the Doctrine\DBAL\Connection::executeQuery() and executeUpdate() methods.
You need to pass the param constants into the third parameter called $types.