chore: enforce that we only visit blocks once with new deque type

[TomAFrench]

Description

Problem*

Resolves

Summary*

We've got this logic in a couple of passes so I thought it would be worth factoring out to ensure that blocks are marked as visited correctly.

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.