Apply backend agnostic ACIR optimization passes separately to backend-specific passes

[TomAFrench]

Problem

In noir-lang/acvm#88, we made the distinction between optimizers (which are generic between backends) and transformers (which use knowledge about the desired proving backend to make the ACIR compatible with it.

Despite this we currently have a single monolithic compile function inside the ACVM which applies both optimizations and transformations.

Happy Case

We should expose optimize and transform (this could be named better) functions to separate these two functions. We could then make use of optimize as a final pass within the Noir compiler so that our outputted ACIR represents the most optimized generic ACIR possible.

This means that our backend step is purely a matter of making the ACIR compatible with the backend rather than a mix of two concepts.

Alternatives Considered

No response

Additional Context

No response

Would you like to submit a PR for this Issue?

No

Support Needs

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[kevaundray]

Can this be closed?

[TomAFrench]

Yep this was closed by #2979