Partial forward port of b1bf8d64 from 1.7.x. Refs #24193.

Refs #14030.

Thanks to Keryn Knight for the report.

Thanks Tim Graham for review

The failure was introduced in Django by
c7fd9b24 and the change in
Python 3.5 is https://hg.python.org/cpython/rev/a3c345ba3563.

varchar()[] cannot compare itself to text[]

Thanks to joelburton for the patch.

Thanks Tomas Dobrovolny for the report and Tim Graham for the review.

Thanks Łukasz Harasimowicz for the report.

Regression introduced in 0f169098

Kept support for creating models without migrations when running tests
(especially for Django's test suite).

Forward port of 8c8a1a08 from stable/1.8.x.