[COREV] Fix generation for clipu from betweenu pattern

Created by: CharKeaney

It appears the definition for the betweenu pattern is erroneous as the use of an unsigned appears to refer to how the output appears and not how the inputs are treated. This causes further problems as the tests for clipu expect this erroneous behaviour.

This patch resolves this issue within the definition of the betweenu pattern and the tests so that generation of the clipu instruction can occur and is tested for successfully. This fixes a failing test.