[ZkTracer] missing test case for `SMOD`

## Description

The issue is that we are missing a test case in the unit tests for `tracer` related to `SMOD`.  Specifically, a case where the numerator is positive but the denominator is negative.  This is an odd case because, with `SDIV`, it would return a negative value.  However, with `SMOD` it returns a positive value.

## Impact

This has no impact as it is simply a missing test.