feat: optimize array reads from length 1 arrays

[TomAFrench]

Description

Problem*

Resolves

Summary*

This optimization deals with a couple of avoidable issues which arose in #9200. If we have a length 1 array then we can just optimistically read from index 0 and inject an assertion that the index will be zero.

This allows us to simplify some later instructions however the results are not shown against master due to #7827 currently injecting constraints which turn all of these array accesses into constant index accesses currently.

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.

[github-actions]

⚠️ Performance Alert ⚠️

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

Benchmark suite	Current: 09613b1	Previous: b331315	Ratio
rollup-base-private	714.77 MB	502.19 MB	1.42
rollup-base-public	601.01 MB	435.05 MB	1.38

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

CC: @TomAFrench

[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: 971dc19	Previous: b331315	Ratio
test_report_AztecProtocol_aztec-packages_noir-projects_noir-protocol-circuits_crates_blob	235 s	170 s	1.38
test_report_zkpassport_noir_rsa_	2 s	1 s	2

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

CC: @TomAFrench

[github-actions]

Changes to number of Brillig opcodes executed

Generated at commit: 1881474aa85ad8cda61457fe37034fb6e0e05d75, compared to commit: b33131574388d836341cea9b6380f3b1a8493eb8

🧾 Summary (10% most significant diffs)

Program	Brillig opcodes (+/-)	%
lambda_from_array_inliner_max	-73 ✅	-4.15%
lambda_from_array_inliner_min	-73 ✅	-4.15%
lambda_from_array_inliner_zero	-73 ✅	-4.15%

---

Full diff report 👇

Program	Brillig opcodes (+/-)	%
lambda_from_array_inliner_max	1,684 (-73)	-4.15%
lambda_from_array_inliner_min	1,684 (-73)	-4.15%
lambda_from_array_inliner_zero	1,684 (-73)	-4.15%

[github-actions]

Changes to Brillig bytecode sizes

Generated at commit: 1881474aa85ad8cda61457fe37034fb6e0e05d75, compared to commit: b33131574388d836341cea9b6380f3b1a8493eb8

🧾 Summary (10% most significant diffs)

Program	Brillig opcodes (+/-)	%
lambda_from_array_inliner_max	-73 ✅	-2.85%
lambda_from_array_inliner_min	-73 ✅	-2.85%
lambda_from_array_inliner_zero	-73 ✅	-2.85%

---

Full diff report 👇

Program	Brillig opcodes (+/-)	%
lambda_from_array_inliner_max	2,484 (-73)	-2.85%
lambda_from_array_inliner_min	2,484 (-73)	-2.85%
lambda_from_array_inliner_zero	2,484 (-73)	-2.85%

[guipublic]

LGTM