Remove Barretenberg specific code/comments from SSA

[kevaundray]

Problem

In certain places in SSA, we mention or apply logic for Barretenberg. One place this happens is when we have an odd range constraint. Since Barretenberg does not support odd range constraints, a much more in-efficient strategy is being used. As opposed to just using the range constraint black box function.

Proposed solution

Barretenberg should be made to deal with odd bit size range constraints in its backend and the code in SSA should be removed so that it does not affect non-barretenberg backends

Alternatives considered

No response

Additional context

No response

Submission Checklist

• Once I hit submit, I will assign this issue to the Project Board with the appropriate tags.

[kevaundray]

This is also the case for starting witness indices at 0.

This however could be something we put into ACIR so that frontends can have a zero value and we make it a standard that Witness(0) refers to 0, and possibly Witness(1) refers to 1. We should then move the methods which increment the Witness to ACIR.

Barretenberg could deal with this by applying one to all witness indices (since the compiler will start off from 0)

[kevaundray]

Before closing this, we should check in ssa folder, if this is still the case