[m-rev.] for review: factor out common code for ops on integer types

[Julien Fischer]

Hi Zoltan,

On Wed, 24 Oct 2018, Zoltan Somogyi wrote:

> For review by Julien, since it affects code he added recently.

How do you define "recently"?  The last significant change I made to that
code was back in February.

The change looks fine.

Julien.