Postgres ordering ARRAY_AGG and STRING_AGG do not support expression.

[Simone Pellizzari]

I found that if you pass and expression as an ordering argument (introduced in ​https://github.com/django/django/commit/96199e562dcc409ab4bdc2b2146fa7cf73c7c5fe) an IndexError: tuple index out of range exception will be thrown when the query is executed.

This is caused by simply ignoring sql_params returned from as_sql elements contained in passed ordering argument.