fix(ssa): Make the lookback feature opt-in

[rkarabut]

Description

Problem

The Brillig constraints check can get slow on large rollout functions, with the recently added lookback feature, while allowing to catch some rare false positives, looking to be the main culprit.

Summary

This PR disables lookback by default and allows the developer to employ it at their discretion. Also, repeated code locations of brillig calls are filtered out, improving performance of the pass.

Additional Context

Documentation*

Check one:

• No documentation needed.
• Documentation included in this PR.
• [For Experimental Features] Documentation to be submitted in a separate PR.

PR Checklist*

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[TomAFrench]

Even prior to the addition of this feature, this pass was causing compilation to hang on the protocol circuits so I'm in favour of making the entire pass opt in.

[rkarabut]

Even prior to the addition of this feature, this pass was causing compilation to hang on the protocol circuits so I'm in favour of making the entire pass opt in.

Alright. Gotta put some additional research into this, as in doing test runs working on the initial check protocol circuits worked fine for me (although I've had word of the hangups later). Removed "resolves #7171" from the description. I think the feature should be opt-in any case though.

[github-actions]

⚠️ Performance Alert ⚠️

Possible performance regression was detected for benchmark 'Test Suite Duration'.
Benchmark result of this commit is worse than the previous benchmark result exceeding threshold 1.20.

Benchmark suite	Current: dfec078	Previous: 130d991	Ratio
noir-lang_noir_check_shuffle_	1 s	0 s	+∞
noir-lang_ec_	1 s	0 s	+∞

This comment was automatically generated by workflow using github-action-benchmark.

CC: @TomAFrench

[rkarabut]

Added filtering for already visited code locations of the brillig calls, which seems to help a lot with huge unrolled functions. Probably could switch the check back as the default.