The attached patch adds fast paths for PyLong division by 1 and -1, as well as dividing 0 by something. This was found helpful for fractions normalisation, as the GCD that is divided by can often be |1|, but firing up the whole division machinery for this eats a lot of CPU cycles for nothing.

There are currently two test failures in test_long.py because dividing a huge number by 1 or -1 no longer raises an OverflowError. This is a behavioural change, but I find it acceptable. If others agree, I'll fix the tests and submit a new patch.