chore: Add missing IfElse simplification cases

[jfecher]

Description

Problem*

Resolves #6878

Summary*

Wanted a separate PR for this change so I could see the effect it had alone

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]

Peak Memory Sample

Program	Peak Memory	%
keccak256	78.48M	0%
workspace	123.81M	0%
regression_4709	422.91M	0%
ram_blowup_regression	1.58G	0%
private-kernel-tail	201.52M	-3%
private-kernel-reset	716.79M	0%
private-kernel-inner	291.60M	0%
parity-root	171.90M	0%

[github-actions]

Execution Sample

Program	Execution Time	%
sha256_regression	0.634s	3%
regression_4709	0.384s	-6%
ram_blowup_regression	4.555s	4%
rollup-base-public	21.576s	3%
rollup-base-private	19.688s	3%
private-kernel-tail	0.708s	1%
private-kernel-reset	1.515s	3%
private-kernel-inner	0.986s	-1%
parity-root	0.524s	-3%

[github-actions]

Compilation Sample

Program	Compilation Time	%
sha256_regression	1.385s	-3%
regression_4709	0.791s	-4%
ram_blowup_regression	15.728s	1%
rollup-base-public	114.708s	-4%
rollup-base-private	95.672s	0%
private-kernel-tail	1.096s	3%
private-kernel-reset	7.667s	4%
private-kernel-inner	2.201s	-5%
parity-root	0.735s	-1%
noir-contracts	89.827s	2%

[jfecher]

Somewhat unclear if this is beneficial or not

[TomAFrench]

Yeah, I think this is a much less likely optimization tbh as we need to get reversed conditions as opposed to being able to simplify all of the if-elses in a particular branch which will naturally share the same condition.

[jfecher]

Closing this for now, it's unclear that it's needed so I'm erring on the side of less code to maintain