nightly-2024-04-07: feat: add `remove_enable_side_effects` SSA pass (#4224)

# Description

## Problem\*

Resolves <!-- Link to GitHub Issue -->

## Summary\*

The `EnableSideEffects` instruction can hamper dead instruction
elimination in the case where it's not covering any instructions which
have side effects (and so are affected by the `EnableSideEffects`
instruction). In this case we cannot perform any DIE on instructions
used to calculate the predicate as the compiler sees their results as
being used.

This PR adds a new SSA pass which delays inserting `EnableSideEffects`
instructions until the next instruction which would be affected by them.
This means that if we hit another `EnableSideEffects` instruction first
then we can omit the previous one, unlocking more DIE opportunities.


## Additional Context



## Documentation\*

Check one:
- [ ] No documentation needed.
- [ ] Documentation included in this PR.
- [ ] **[Exceptional Case]** Documentation to be submitted in a separate
PR.

# PR Checklist\*

- [ ] I have tested the changes locally.
- [ ] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.

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Co-authored-by: jfecher <[email protected]>